ORCID Profile
0000-0001-8672-9297
Current Organisations
Queensland University of Technology (QUT)
,
CSIRO
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Publisher: AIP Publishing
Date: 09-2010
DOI: 10.1063/1.3475728
Abstract: The possibility to discriminate between the relative importance of the fluxes of energy and matter in plasma-surface interaction is demonstrated by the energy flux measurements in low-temperature plasmas ignited by the radio frequency discharge (power and pressure ranges 50–250 W and 8–11.5 Pa) in Ar, Ar+H2, and Ar+H2+CH4 gas mixtures typically used in nanoscale synthesis and processing of silicon- and carbon-based nanostructures. It is shown that by varying the gas composition and pressure, the discharge power, and the surface bias one can effectively control the surface temperature and the matter supply rates. The experimental findings are explained in terms of the plasma-specific reactions in the plasma bulk and on the surface.
Publisher: Elsevier BV
Date: 04-2016
Publisher: IOP Publishing
Date: 09-2017
Publisher: Elsevier BV
Date: 07-2020
Publisher: IOP Publishing
Date: 12-1995
Publisher: Elsevier BV
Date: 02-2005
Publisher: Wiley
Date: 1994
Publisher: AIP Publishing
Date: 25-05-2009
DOI: 10.1063/1.3147193
Publisher: AIP Publishing
Date: 15-02-2012
DOI: 10.1063/1.3688252
Abstract: Nitrogenated carbon nanotips (NCNTPs) are synthesized by plasma-enhanced hot filament chemical vapor deposition from the hydrogen, methane, and nitrogen gas mixtures with different flow rate ratios of hydrogen to nitrogen. The morphological, structural, compositional, and electron field emission (EFE) properties of the NCNTPs were investigated by field emission scanning electron microscopy, Raman spectroscopy, x ray photoelectron spectroscopy, and EFE high-vacuum system. It is shown that the NCNTPs deposited at an intermediate flow rate ratio of hydrogen to nitrogen feature the best size/shape and pattern uniformity, the highest nanotip density, the highest nitrogen concentration, as well as the best electron field emission performance. Several factors that come into play along with the nitrogen incorporation, such as the combined effect of the plasma sputtering and etching, the transition of sp3 carbon clusters to sp2 carbon clusters, the increase of the size of the sp2 clusters, as well as the reduction of the work function, have been examined to interpret these experimental findings. Our results are highly relevant to the development of the next generation electron field emitters, flat panel displays, atomic force microscope probes, and several other advanced applications.
Publisher: IOP Publishing
Date: 04-06-2021
Abstract: Dual argon plasmas ignited by one direct current power source are used to treat an aqueous solution of hydrogen tetrachloroaurate-(III) trihydrate (HAuCl 4 · 3H 2 O) which is contained in an H-type electrochemical cell. The solution contained in one cell acts as a cathode, and in the other as an anode. Experiments are carried out to directly visualize the formation process of gold nanoparticles (AuNPs) in separated cells of the H-type electrochemical reactor. The results and analyzes suggest that hydrogen peroxide and hydrated electrons generated from the plasma-liquid interactions play the roles of reductants in the solutions, respectively. Hydrogen peroxide can be generated in the case of the liquid being a cathode or an anode, while most of hydrated electrons are formed in the case of the liquid being an anode. Therefore, the reduction of the AuCl 4 − ions is mostly attributed to the hydrogen peroxide as the liquid acts as a cathode, while to the hydrogen peroxide and hydrated electrons as the liquid acts as an anode. Moreover, the pH value of the solution can be used to tune the formation processes and the final form of the AuNPs due to its mediation of reductants.
Publisher: AIP Publishing
Date: 2006
DOI: 10.1063/1.2136416
Abstract: Plasma transport in a hybrid dc vacuum arc plasma source for ion deposition and plasma immersion treatment is considered. It is found that external crossed electric and magnetic fields near the substrate can significantly reduce the relative litude of ion current fluctuations I¯f at the substrate surface. In particular, I¯f decreases with the applied magnetic field when the bias voltage exceeds 300V, thus allowing one to reduce the deviations from the rated process parameters. This phenomenon can be attributed to an interaction between the metal-plasma jet from the arc source and the discharge plasma in the crossed fields.
Publisher: Wiley
Date: 13-08-2009
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6RA05737C
Abstract: Oriented MoSe 2 nanosheets with varying layers and structures were synthesized on silicon substrates by hot filament chemical vapour deposition in a nitrogen environment using MoO 3 and Se powders as precursors.
Publisher: AIP Publishing
Date: 10-2005
DOI: 10.1063/1.2102868
Abstract: Manipulation of a single nanoparticle in the near-substrate areas of high-density plasmas of low-temperature glow discharges is studied. It is shown that the nanoparticles can be efficiently manipulated by the thermophoretic force controlled by external heating of the substrate stage. Particle deposition onto or repulsion from nanostructured carbon surfaces critically depends on the values of the neutral gas temperature gradient in the near-substrate areas, which is directly measured in situ in different heating regimes by originally developed temperature gradient probe. The measured values of the near-surface temperature gradient are used in the numerical model of nanoparticle dynamics in a variable-length presheath. Specific conditions enabling the nanoparticle to overcome the repulsive potential and deposit on the substrate during the discharge operation are investigated. The results are relevant to fabrication of various nanostructured films employing structural incorporation of the plasma-grown nanoparticles, in particular, to nanoparticle deposition in the plasma-enhanced chemical-vapor deposition of carbon nanostructures in hydrocarbon-based plasmas.
Publisher: AIP Publishing
Date: 29-03-2017
DOI: 10.1063/1.4979263
Abstract: The breakdown delay time of a closed plasma plume excited by a high-voltage pulse is investigated. The visible monochromatic light of 404, 532, and 662 nm wavelength and narrow-waveband light at a central wavelength of 400, 430, 450, 470, 500, 530, 570, 610, and 630 nm are used to pre-ionize the gas. It is found that the breakdown delay time decreases when the visible light illuminates the discharge tube. The light is most effective when it is applied at the position near the high-voltage electrode. Besides, the tube material and size are important for enhancing the effect. The jet using quartz tube and larger inner diameter make the effect stronger. The effect of visible light is found to inversely relate to the wavelength, manifested by the longer breakdown delay times for longer wavelengths. With increasing the frequency and the pulse width of the voltage, the visible light shortens the delay time more effectively. These observations can be explained by the visible light-enhanced generation of free electrons before the ignition. The proposed mechanisms of free-electron generation are the optically stimulated exoelectron emission from the inner surface of the discharge tube wall and the vibrational excitation of nitrogen molecules. The effects of visible light weaken with the addition of oxygen as a result of electron affinity to oxygen.
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2CC35151J
Abstract: Sub-oxide-to-metallic highly-crystalline nanowires with uniformly distributed nanopores in the 3 nm range have been synthesized by a unique combination of the plasma oxidation, re-deposition and electron-beam reduction. Electron beam exposure-controlled oxide → sub-oxide → metal transition is explained using a non-equilibrium model.
Publisher: American Chemical Society (ACS)
Date: 21-11-2017
Abstract: Two-dimensional molybdenum disulfide (MoS
Publisher: Elsevier BV
Date: 06-2022
Publisher: MDPI AG
Date: 05-11-2021
DOI: 10.3390/NANO11112977
Abstract: Dental implants are used broadly in dental clinics as the most natural-looking restoration option for replacing missing or highly diseased teeth. However, dental implant failure is a crucial issue for diabetic patients in need of dentition restoration, particularly when a lack of osseointegration and immunoregulatory incompetency occur during the healing phase, resulting in infection and fibrous encapsulation. Bio-inspired or biomimetic materials, which can mimic the characteristics of natural elements, are being investigated for use in the implant industry. This review discusses different biomimetic dental implants in terms of structural changes that enable antibacterial properties, drug delivery, immunomodulation, and osseointegration. We subsequently summarize the modification of dental implants for diabetes patients utilizing carbon nanomaterials, which have been recently found to improve the characteristics of biomimetic dental implants, including through antibacterial and anti-inflammatory capabilities, and by offering drug delivery properties that are essential for the success of dental implants.
Publisher: Elsevier BV
Date: 03-2022
DOI: 10.1016/J.CHEMOSPHERE.2021.132757
Abstract: Antibiotics have been extensively used as pharmaceuticals for erse applications. However, their overuse and indiscriminate discharge to water systems have led to increased antibiotic levels in our aquatic environments, which poses risks to human and livestock health. Non-thermal plasma water. However, the issues of process scalability and the mechanisms towards understanding the plasma-induced degradation remain. This study addresses these issues by coupling a non-thermal plasma jet with a continuous flow reactor to reveal the effective mechanisms of amoxicillin degradation. Four industry-relevant feeding gases (nitrogen, air, argon, and oxygen), discharge voltages, and frequencies were assessed. Amoxicillin degradation efficiencies achieved using nitrogen and air were much higher compared to argon and oxygen and further improved by increasing the applied voltage and frequency. The efficiency of plasma-induced degradation depended on the interplay of hydrogen peroxide (H
Publisher: AIP Publishing
Date: 2008
DOI: 10.1063/1.2836621
Abstract: The excitation of pairs of electron surface waves via nonresonant decay of plasma waves incident onto a solid surface is studied in the context of controlling the interaction of pulsed electromagnetic radiation with plasma-exposed solid surfaces. The role of the plasma-exposed surfaces in nonlinear heating of the plasma edge and related power transfer is discussed. It is shown that the maximum efficiency of the power transfer at solid surfaces with dielectric permittivity εd& corresponds to the resonant two-surface wave decay. On the other hand, for solids with εd& the maximum power transfer efficiency is achieved through nonresonant excitation of the quasistatic surface waves. In this case the plasma waves generated by external radiation dissipate their energy into the plasma periphery most effectively.
Publisher: American Chemical Society (ACS)
Date: 12-08-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C2TC00560C
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C0CE00972E
Publisher: Bentham Science Publishers Ltd.
Date: 26-08-2016
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D2NA00863G
Abstract: Supercapacitor is a promising energy storage device for short term energy storage system (ESSs). This review, covers materials and electrolyte tailoring needed to achieve high V supercapacitor, essential for designing an efficient short term ESSs.
Publisher: No publisher found
Date: 2021
Publisher: Wiley
Date: 05-07-2007
Publisher: American Chemical Society (ACS)
Date: 29-10-2019
Abstract: Oil spills remain a worldwide challenge and need emergency "spill-SOS" actions when they occur. Conventional methods suffer from complex processes and high cost. Here, we demonstrate a solar-heating siphon-capillary oil skimmer (S-SOS) that harvests solar energy, gravitational potential energy, and solid surface energy to enable efficient oil spill recovery in a self-pumping manner. The S-SOS is assembled by an inverted U-shape porous architecture combining solar-heating, siphon, and capillary effects, and works without any external power or manual interventions. Importantly, solid surface energy is used by capillary adsorption to enable the self-starting behavior, gravitational potential energy is utilized by siphon transport to drive the oil flow, and solar energy is harvested by solar-thermal conversion to facilitate the transport speed. In the proof-of-concept work, an all-carbon hierarchical architecture (VG/GF) is fabricated by growing vertically oriented graphene nanosheets (VGs) on a monolith of graphite felt (GF) via a plasma-enhanced method to serve as the U-shape architecture. Consequently, an oil-recovery rate of 35.2 L m
Publisher: IOP Publishing
Date: 20-06-2016
Publisher: Wiley
Date: 12-04-2011
Publisher: AIP Publishing
Date: 03-03-2014
DOI: 10.1063/1.4867891
Publisher: Wiley
Date: 09-11-2016
Publisher: Springer Science and Business Media LLC
Date: 12-03-2021
Publisher: Elsevier BV
Date: 11-2021
Publisher: Elsevier BV
Date: 10-2015
Publisher: Wiley
Date: 04-09-2018
Abstract: This work demonstrates the effect of oxygen vacancies in SnO
Publisher: Elsevier BV
Date: 04-2014
Publisher: IOP Publishing
Date: 14-07-2020
Publisher: Elsevier BV
Date: 09-2015
Publisher: American Vacuum Society
Date: 09-2000
DOI: 10.1116/1.1286142
Abstract: Global electric properties, distributions of the induced electromagnetic fields, electron density, temperature, and plasma potential in the 500 kHz planar-coil inductively coupled plasma source have been investigated. The transitions between the two (E and H) discharge operating regimes with variation of input power and operating gas pressure have been demonstrated. It has been shown that the E↔H transitions are accompanied by the resonant minima in the rf power reflection coefficient, which are characteristic for mode jumps in electron cyclotron resonance and microwave slot-excited discharges. The optical emission spectra of argon atoms and ions together with global power balance arguments suggest that the step-wise ionization via the excited states of argon atoms and ions is presumably a mechanism which is responsible for hysteresis. The achieved high plasma density with a high homogeneity level, and low electron temperature and plasma potential imply that the studied plasma source is promising for industrial applications.
Publisher: American Chemical Society (ACS)
Date: 09-06-2020
Publisher: American Chemical Society (ACS)
Date: 21-02-2012
DOI: 10.1021/JA210813S
Abstract: The possibility of fast, narrow-size/chirality nucleation of thin single-walled carbon nanotubes (SWCNTs) at low, device-tolerant process temperatures in a plasma-enhanced chemical vapor deposition (CVD) is demonstrated using multiphase, multiscale numerical experiments. These effects are due to the unique nanoscale reactive plasma chemistry (NRPC) on the surfaces and within Au catalyst nanoparticles. The computed three-dimensional process parameter maps link the nanotube incubation times and the relative differences between the incubation times of SWCNTs of different sizes/chiralities to the main plasma- and precursor gas-specific parameters and explain recent experimental observations. It is shown that the unique NRPC leads not only to much faster nucleation of thin nanotubes at much lower process temperatures, but also to better selectivity between the incubation times of SWCNTs with different sizes and chiralities, compared to thermal CVD. These results are used to propose a time-programmed kinetic approach based on fast-responding plasmas which control the size-selective, narrow-chirality nucleation and growth of thin SWCNTs. This approach is generic and can be used for other nanostructure and materials systems.
Publisher: American Chemical Society (ACS)
Date: 07-05-2012
DOI: 10.1021/CG300103A
Publisher: ISCA
Date: 2018
DOI: 10.21437/SLTU.2018
Publisher: Elsevier BV
Date: 2010
Publisher: Elsevier BV
Date: 2021
Publisher: American Chemical Society (ACS)
Date: 16-12-2022
Publisher: IOP Publishing
Date: 12-10-2022
Abstract: This work reported an air atmospheric pressure plasma jet served as an ion source for nonvolatile solid analysis, which allows a unique capability to achieve thermal desorption and ionization simultaneously without complex devices, inert gas, or solvents. Owing to precise amount of heat generated by plasma jet, nonvolatile analytes were thermally released from solid surfaces without the assistance of secondary desorption equipment. According to the mass spectra and Fourier transform infrared spectrum, [M + H] + and [M + NO 3 ] − ions were the major analyte ions in the positive-ion and negative-ion modes, respectively. The applied voltages, discharge currents, and gas temperatures of plasma jet were measured, and found to be positively correlated with the mass spectra signal intensity of the s les, while the added resistances and gas flow rate were negatively correlated with the signal intensity. The influence mechanisms of analytes natures coupling physical parameters of plasma jet on detection performance were revealed. The prospect of quantitative testing was confirmed by the linear relationship between the peak intensity and s le mass.
Publisher: AIP
Date: 2005
DOI: 10.1063/1.2134661
Publisher: American Scientific Publishers
Date: 10-2010
Abstract: This article quantifies the effect of the operating pressure of the H2 + C2H4 gas mixture on the current density and threshold voltage of the electron emission from dense forests of multiwalled carbon nanotubes synthesized using thermal catalytic Chemical Vapor Deposition under near atmospheric pressure process conditions. The results suggest that in the pressure range of interest 400-700 Torr the field emission properties can be substantially improved by operating the process at lower gas pressures when the nanostructure aspect ratios are higher. The obtained threshold voltage approximately 1.75 V/microm and the emission current densities approximately 10 mA/cm2 offer competitive advantages compared with the results reported by other authors.
Publisher: American Chemical Society (ACS)
Date: 04-12-2018
Publisher: Elsevier BV
Date: 02-2020
Publisher: AIP Publishing
Date: 19-12-2011
DOI: 10.1063/1.3669534
Abstract: Room-temperature, atmospheric-pressure plasma needle treatment is used to effectively minimize the adenovirus (AdV) infectivity as quantified by the dramatic reduction of its gene expression in HEK 293A primary human embryonic kidney cells studied by green fluorescent protein imaging. The AdV titer is reduced by two orders of magnitude within only 8 min of the plasma exposure. This effect is due to longer lifetimes and higher interaction efficacy of the plasma-generated reactive species in confined space exposed to the plasma rather than thermal effects commonly utilized in pathogen inactivation. This generic approach is promising for the next-generation anti-viral treatments and imunotherapies.
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3NR00550J
Abstract: We report on the comparative study of magnetotransport properties of large-area vertical few-layer graphene networks with different morphologies, measured in a strong (up to 10 T) magnetic field over a wide temperature range. The petal-like and tree-like graphene networks grown by a plasma enhanced CVD process on a thin (500 nm) silicon oxide layer supported by a silicon wafer demonstrate a significant difference in the resistance-magnetic field dependencies at temperatures ranging from 2 to 200 K. This behaviour is explained in terms of the effect of electron scattering at ultra-long reactive edges and ultra-dense boundaries of the graphene nanowalls. Our results pave a way towards three-dimensional vertical graphene-based magnetoelectronic nanodevices with morphology-tuneable anisotropic magnetic properties.
Publisher: Springer Science and Business Media LLC
Date: 03-1995
DOI: 10.1007/BF02066880
Publisher: Wiley
Date: 14-12-2018
Publisher: MDPI AG
Date: 26-01-2021
DOI: 10.3390/S21030810
Abstract: Surface-enhanced Raman spectroscopy (SERS) technology is an attractive method for the prompt and accurate on-site screening of illicit drugs. As portable Raman systems are available for on-site screening, the readiness of SERS technology for sensing applications is predominantly dependent on the accuracy, stability and cost-effectiveness of the SERS strip. An atmospheric-pressure plasma-assisted chemical deposition process that can deposit an even distribution of nanogold particles in a one-step process has been developed. The process was used to print a nanogold film on a paper-based substrate using a HAuCl4 solution precursor. X-ray photoelectron spectroscopy (XPS) analysis demonstrates that the gold has been fully reduced and that subsequent plasma post-treatment decreases the carbon content of the film. Results for cocaine detection using this substrate were compared with two commercial SERS substrates, one based on nanogold on paper and the currently available best commercial SERS substrate based on an Ag pillar structure. A larger number of bands associated with cocaine was detected using the plasma-printed substrate than the commercial substrates across a range of cocaine concentrations from 1 to 5000 ng/mL. A detection limit as low as 1 ng/mL cocaine with high spatial uniformity was demonstrated with the plasma-printed substrate. It is shown that the plasma-printed substrate can be produced at a much lower cost than the price of the commercial substrate.
Publisher: American Scientific Publishers
Date: 05-2013
Abstract: The present study compares the effects of two different material processing techniques on modifying hydrophilic SiO2 nanoparticles. In one method, the nanoparticles undergo plasma treatment by using a custom-developed atmospheric-pressure non-equilibrium plasma reactor. With the other method, they undergo chemical treatment which grafts silane groups onto their surface and turns them into hydrophobic. The treated nanoparticles are then used to synthesize epoxy resin-based nanocomposites for electrical insulation applications. Their characteristics are investigated and compared with the pure epoxy resin and nanocomposite fabricated with unmodified nanofillers counterparts. The dispersion features of the nanoparticles in the epoxy resin matrix are examined through scanning electron microscopy (SEM) images. All s les show evidence that the agglomerations are smaller than 30 nm in their diameters. This indicates good dispersion uniformity. The Weibull plot of breakdown strength and the recorded partial discharge (PD) events of the epoxy resin lasma-treated hydrophilic SiO2 nanocomposite (ER/PTI) suggest that the plasma-treated specimen yields higher breakdown strength and lower PD magnitude as compared to the untreated ones. In contrast, surprisingly, lower breakdown strength is found for the nanocomposite made by the chemically treated hydrophobic particles, whereas the PD magnitude and PD numbers remain at a similar level as the plasma-treated ones.
Publisher: Elsevier BV
Date: 12-2020
Publisher: Elsevier BV
Date: 11-2019
Publisher: Springer Science and Business Media LLC
Date: 26-02-2018
DOI: 10.1038/S41467-018-03316-7
Abstract: Exposed to ionizing radiation, nanomaterials often undergo unusual transformations compared to their bulk form. However, atomic-level mechanisms of such transformations are largely unknown. This work visualizes and quantifies nanopore shrinkage in nanoporous alumina subjected to low-energy ion beams in a helium ion microscope. Mass transport in porous alumina is thus simultaneously induced and imaged with nanoscale precision, thereby relating nanoscale interactions to mesoscopic deformations. The interplay between chemical bonds, disorders, and ionization-induced transformations is analyzed. It is found that irradiation-induced diffusion is responsible for mass transport and that the ionization affects mobility of diffusive entities. The extraordinary room temperature superplasticity of the normally brittle alumina is discovered. These findings enable the effective manipulation of chemical bonds and structural order by nanoscale ion-matter interactions to produce mesoscopic structures with nanometer precision, such as ultra-high density arrays of sub-10-nm pores with or without the accompanying controlled plastic deformations.
Publisher: SPIE
Date: 22-12-2015
DOI: 10.1117/12.2220785
Publisher: IOP Publishing
Date: 29-04-2021
Abstract: The quantification of hydrogen peroxide (H 2 O 2 ) generated in the plasma-liquid interactions is of great importance, since the H 2 O 2 species is vital for the applications of the plasma-liquid system. Herein, we report on in situ quantification of the aqueous H 2 O 2 (H 2 O 2aq ) using a colorimetric method for the DC plasma-liquid systems with liquid as either a cathode or an anode. The results show that the H 2 O 2aq yield is 8–12 times larger when the liquid acts as a cathode than when the liquid acts as an anode. The conversion rate of the gaseous OH radicals to H 2 O 2aq is 4–6 times greater in the former case. However, the concentrations of dissolved OH radicals for both liquid as cathode and anode are of the same order of tens of nM.
Publisher: Elsevier BV
Date: 05-2019
Publisher: American Chemical Society (ACS)
Date: 26-10-2023
Publisher: Springer Science and Business Media LLC
Date: 24-01-2019
DOI: 10.1038/S41598-018-37132-2
Abstract: Developing of lead-free double perovskites have drawn significant interest for photovoltaics and optoelectronics as the materials have the potential to avoid toxicity and instability issues associated with lead-based organometallic perovskites. In this study, we report the optoelectronic properties of a new group of non-toxic lead-free organic-inorganic halide double perovskites composed of caesium (Cs), methylammonium (MA) or formamidinium (FA) with bismuth (Bi) and metal copper (Cu). We perform density functional theory investigations to calculate the structural, electronic and optical properties of 18 Pb-free compounds, ABiCuX 6 [A = Cs 2 , (MA) 2 , (FA) 2 , CsMA, CsFA, MAFA X = I, Br, Cl] to predict their suitability in photovoltaic and optoelectronic applications. We found that the considered compounds are semiconductors with a tunable band gap characteristics that are suitable for some devices like light emitting diodes. In addition to this, the high dielectric constant, high absorption, high optical conductivity and low reflectivity suggest that the materials have the potential in a wide range of optoelectronic applications including solar cells. Furthermore, we predict that the organic-inorganic hybrid double perovskite (FA) 2 BiCuI 6 is the best candidate in photovoltaic and optoelectronic applications as the material has superior optical and electronic properties.
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1NR05691C
Abstract: Vacancy defect engineering of BiVO 4 photoanodes including the generation of oxygen vacancies, vanadium vacancies, and bismuth vacancies can tune the electronic structure, promote charge separation, and increase surface photoreaction kinetics.
Publisher: Elsevier BV
Date: 10-2019
Publisher: Elsevier BV
Date: 02-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2010
DOI: 10.1039/B9NR00322C
Abstract: Random blinking is a major problem on the way to successful applications of semiconducting nanocrystals in optoelectronics and photonics, which until recently had neither a practical solution nor a theoretical interpretation. An experimental breakthrough has recently been made by fabricating non-blinking Cd(1-x)Zn(x)Se/ZnSe graded nanocrystals [Wang et al., Nature, 2009, 459, 686]. Here, we (1) report an unequivocal and detailed theoretical investigation to understand the properties (e.g., profile) of the potential-well and the distribution of Zn content with respect to the nanocrystal radius and (2) develop a strategy to find the relationship between the photoluminescence (PL) energy peaks and the potential-well due to Zn distribution in nanocrystals. It is demonstrated that the non-square-well potential can be varied in such a way that one can indeed control the PL intensity and the energy-level difference (PL energy peaks) accurately. This implies that one can either suppress the blinking altogether, or alternatively, manipulate the PL energy peaks and intensities systematically to achieve a controlled non-random intermittent luminescence. The approach developed here is based on the ionization energy approximation and as such is generic and can be applied to any non-free-electron nanocrystals.
Publisher: AIP Publishing
Date: 05-2010
DOI: 10.1063/1.3431098
Abstract: Current-voltage characteristics of the planar magnetron are studied experimentally and by numerical simulation. Based on the measured current-voltage characteristics, a model of the planar magnetron discharge is developed with the background gas pressure and magnetic field used as parameters. The discharge pressure was varied in a range of 0.7–1.7 Pa, the magnetic field of the magnetron was of 0.033–0.12 T near the cathode surface, the discharge current was from 1 to 25 A, and the magnetic field lines were tangential to the substrate surface in the region of the magnetron discharge ignition. The discharge model describes the motion of energetic secondary electrons that gain energy by passing the cathode sheath across the magnetic field, and the power required to sustain the plasma generation in the bulk. The plasma electrons, in turn, are accelerated in the electric field and ionize effectively the background gas species. The model is based on the assumption about the prevailing Bohm mechanism of electron conductivity across the magnetic field. A criterion of the self-sustained discharge ignition is used to establish the dependence of the discharge voltage on the discharge current. The dependence of the background gas density on the current is also observed from the experiment. The model is consistent with the experimental results.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8TA10952D
Abstract: Developing highly active electrocatalysts with rich oxygen vacancies and precisely distributed metal sites holds exceptional promise for various renewable and sustainable energy technologies.
Publisher: American Scientific Publishers
Date: 11-2008
Abstract: The paper presents results of comparative investigation of carbon nanotubes growth processes in dense low-temperature plasma and on substrate surface. Hybrid/Monte-Carlo numerical simulations were used to demonstrate the differences in the ion fluxes, growth rates and kinetics of adsorbed atoms re-distribution on substrate and nanotubes surfaces. We show that the plasma parameters significantly affect the nanotubes growth kinetics. We demonstrate that the growth rates of the nanotubes in plasma and on surface can differ by three orders, and the specific fluxes to the nanotube in the plasma can exceed the flux to surface-grown nanotube by six orders. We also show that the metal catalyst used for the nanotubes production on surface and in arc is a subject to very different conditions and this may be a key factor for the nanotube growth mode. The obtained dependencies for the ion fluxes to the nanotubes and nanotubes growth rates on the plasma parameters may be useful for selection of the production methods.
Publisher: IEEE
Date: 06-2012
Publisher: Elsevier BV
Date: 06-2018
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-2014
Publisher: Elsevier BV
Date: 02-2021
Publisher: AIP Publishing
Date: 17-07-2018
DOI: 10.1063/1.5036704
Abstract: Atmospheric pressure plasma jet arrays can expand the treatment dimension of a single jet to large scales effectively, and the arrays with a good downstream uniformity have a great potential for applications in the materials surface treatment and biomedicine. In this paper, a linear-field jet array with a ring-ring electrode structure in Ar is excited by alternating current (AC) and nanosecond (ns) pulse voltage, and the characteristics and downstream uniformity of the array and their dependence on the applied voltage and gas flow rate are investigated and compared through optical, electrical, and Schlieren diagnosis. The electrical and hydrodynamic interactions between the jets in the array are analyzed and discussed. The results show that the ns pulse excited jet arrays can generate relatively large-scale plasma with better uniformity, longer plumes, and higher intensity active species with a higher energy efficiency than the AC excited ones. No visible deviation of the plume and gas flow trajectories in the light emission and Schlieren images is observed for the ns pulse excited arrays. On the other hand, deviation of plume trajectories is shown to depend on the applied voltage and the gas flow rate for the AC excited arrays. The shorter duration of the interaction of the ns pulse excited jet arrays compared with that of the AC excited jet arrays results in the weaker effects of the Coulomb repellence force and the gas heating, which helps to maintain the uniformity of jet arrays. The reported results can help to design controllable and scalable plasma jet arrays in the economic Ar with good uniformity and higher energy efficiency for material surface and biomedical treatments.
Publisher: Springer Science and Business Media LLC
Date: 05-2016
DOI: 10.1038/AM.2016.44
Publisher: Wiley
Date: 17-08-2018
Publisher: Elsevier BV
Date: 09-2007
Publisher: IOP Publishing
Date: 04-06-2009
Publisher: Elsevier BV
Date: 2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8GC03655A
Abstract: An oxidation–hydrogenation process using atmospheric O 2 has been developed to convert native bagasse lignin into bio-aromatic esters in a single step.
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C4GC02135E
Abstract: Vertical graphene nanosheets (VGS) transformed from honeycomb are used for high-performance supercapacitors and selective detection of amyloid-beta (Aβ) species.
Publisher: AIP Publishing
Date: 08-2007
DOI: 10.1063/1.2769966
Publisher: American Physical Society (APS)
Date: 13-01-2010
Publisher: Elsevier BV
Date: 05-2017
Publisher: Elsevier BV
Date: 20-10-190728635
Publisher: American Chemical Society (ACS)
Date: 08-04-2009
DOI: 10.1021/CG900176C
Publisher: American Chemical Society (ACS)
Date: 02-07-2009
DOI: 10.1021/JP9047083
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D0CC06768G
Abstract: β-Cyclodextrin nanospheres are synthesized through a new strategy and demonstrate excellent performance as alkali-responsive nanocarriers and selective antibiotic adsorbents.
Publisher: The Electrochemical Society
Date: 12-2021
Abstract: The interactions between discharge plasmas and an aqueous solutions can enable the production of reactive species and charge transfer at the plasma-liquid interface, forming the plasma electrochemical system (PES). The PES are promising for erse applications, such as nanomaterials synthesis, due to the activation of the solution chemistry by the plasma. In this paper, we investigate the influence of the solution’s pH value on the formation of silver nanoparticles (AgNPs) in a direct current (DC) PES. Dual argon DC plasmas are generated in an H-type electrochemical cell containing an aqueous solution of silver nitrate with pH values in the range of 1.99–10.71. By this design, the solution acts as a cathode at one end of the H-type cell, and as an anode at the other end. The results show that the AgNPs are formed at the anode except for the solution with the pH value of 1.99. However, at the cathode, the AgNPs only appear in the solution with the pH value of 10.71. We find that the solvated electrons and hydrogen peroxide produced by the plasma-liquid interactions are responsible for the Ag + reduction at the solution anode and the solution cathode, respectively.
Publisher: Elsevier BV
Date: 10-2019
Publisher: American Chemical Society (ACS)
Date: 04-09-2018
Publisher: Elsevier BV
Date: 11-2017
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-2015
Publisher: MDPI AG
Date: 13-11-2020
Abstract: Rich in reactive oxygen and nitrogen species, cold atmospheric plasma has been shown to effectively control events critical to cancer progression selectively inducing apoptosis, reducing tumor volume and vasculature, and halting metastasis by taking advantage of, e.g., synergies between hydrogen peroxide and nitrites. This paper discusses the efficacy, safety and administration of cold atmospheric plasma treatment as a potential tool against cancers, with a focus on the mechanisms by which cold atmospheric plasma may affect critical transitional switches that govern tumorigenesis: the life/death control, tumor angiogenesis and epithelial–mesenchymal transition, and drug sensitivity spectrum. We introduce the possibility of modeling cell transitions between the normal and cancerous states using cold atmospheric plasma as a novel research avenue to enhance our understanding of plasma-aided control of oncogenesis.
Publisher: PUBLISHED BY IMPERIAL COLLEGE PRESS AND DISTRIBUTED BY WORLD SCIENTIFIC PUBLISHING CO.
Date: 09-2005
DOI: 10.1142/P397
Publisher: Hindawi Limited
Date: 06-09-2022
DOI: 10.1002/ER.7249
Publisher: AIP Publishing
Date: 02-2022
DOI: 10.1063/5.0064301
Abstract: Physico-chemical and biological effects of atmospheric pressure plasmas (APPs) find numerous applications in biotechnology, medicine, and other fields. Recent studies revealed APPs’ potential for ischemic stroke treatment through the protection of neuronal cells from injuries. However, the mechanisms of the plasma neuroprotection effects still remain unknown. This study reveals the key mechanisms of APP plasma jet (APPJ) enabled reduction of neuronal cell death caused by oxygen and glucose deprivation (OGD) under stroke-relevant conditions. Plasma reduced OGD induced apoptosis of SH-SY5Y neuronal cells is based on reactive oxygen and nitrogen species production and on nitric oxide related activation of the cyclic guanosine monophosphate (cGMP) and cGMP-dependent protein kinase G (PKG) pathway, followed by the Bcl-2/Bax level modulation and caspase3/9 activity inhibition. In addition, the protective effect of APPJ treatment on OGD injured SH-SY5Y cells could be abolished by cGMP pathway inhibitor LY83583 pretreatment. Collectively, our findings highlight that the mechanism of the neuroprotection effects of the plasma treatment is closely related to the intracellular cGMP/PKG pathway, which provide experimental and theoretical references for future studies on plasma medicine.
Publisher: AIP Publishing
Date: 15-07-2011
DOI: 10.1063/1.3610497
Abstract: Using a multiple plasma deposition-annealing (MDA) technique, we have fabricated an Au nanoisland-based thin film nanoresistor with a very low temperature coefficient of electrical resistivity in a cryogenic-to-room temperature range of 10 to 300 K. The nanoislanded gold film was deposited on a SiO2/Si wafer (500 nm SiO2 thickness) between two 300 nm thick Au electrodes which were separated by 100 m. A sophisticated selection of the thickness of the nanoislanded gold film, the annealing temperature, as well as the number of deposition/annealing cycles resulted in the fabrication of a nanoresistor with a temperature coefficient of electrical resistivity of 2.1 × 10−3 K−1 and the resistivity deviation not exceeding 2% in a cryogenic-to-room temperature range. We have found that the constant resistivity regime of the nanoisland-based thin film nanoresistor corresponds to a minimized nanoisland activation energy (approximately 0.3 meV). This energy can be minimized by reducing the nearest neighbor distance and increasing the size of the Au nanoislands in the optimized nanoresistor structure. It is shown that the constant resistivity nanoresistor operates in the regime where the thermally activated electron tunneling is compensated by the negative temperature dependence of the metallic-type conductivity of nanoislands. Our results are relevant to the development of commercially viable methods of nanoresistor production for various nanoelectronics-based devices. The proposed MDA technique also provides the opportunity to fabricate large arrays of metallic nanoparticles with controllable size, shapes and inter-nanoparticle gaps.
Publisher: Institution of Engineering and Technology (IET)
Date: 09-2017
Publisher: AIP Publishing
Date: 05-2008
DOI: 10.1063/1.2919712
Abstract: The ability to control the properties of single-wall nanotubes (SWNTs) produced in the arc discharge is important for many practical applications. Our experiments suggest that the length of SWNTs significantly increases (up to 4000 nm), along with the purity of the carbon deposit, when the magnetic field is applied to arc discharge. Scanning electron microscopy and transmission electron microscopy analyses have demonstrated that the carbon deposit produced in the magnetic-field-enhanced arc mainly consists of the isolated and bunched SWNTs. A model of a carbon nanotube interaction and growth in the thermal plasma was developed, which considers several important effects such as anode ablation that supplies the carbon plasma in an anodic arc discharge technique, and the momentum, charge, and energy transfer processes between nanotube and plasma. It is shown that the nanotube charge with respect to the plasma as well as nanotube length depend on plasma density and electric field in the interelectrode gap. For instance, nanotube charge changes from negative to positive value with an electron density decrease. The numerical simulations based on the Monte Carlo technique were performed, which explain an increase in the nanotubes produced in the magnetic-field-enhanced arc discharge.
Publisher: AIP Publishing
Date: 23-04-2007
DOI: 10.1063/1.2731728
Abstract: Despite major advances in the fabrication and characterization of SiC and related materials, there has been no convincing evidence of the synthesis of nanodevice-quality nanoislanded SiC films at low, ultralarge scale integration technology–compatible process temperatures. The authors report on a low-temperature (400°C) plasma-assisted rf magnetron sputtering deposition of high-quality nanocrystalline SiC films made of uniform-size nanoislands that almost completely cover the Si(100) surface. These nanoislands are chemically pure, highly stoichiometric, have a typical size of 20–35nm, and contain small (∼5nm) nanocrystalline inclusions. The properties of nanocrystalline SiC films can be effectively controlled by the plasma parameters.
Publisher: AIP Publishing
Date: 2018
DOI: 10.1063/1.5010993
Abstract: In recent years, the use of shielding gas to prevent the diffusion of the ambient air, particularly oxygen and nitrogen species, into the effluent of the atmospheric pressure plasma jet, and thus control the nature of chemical species used in the plasma treatment has increased. In this paper, the radial propagation of a plasma jet in ambient Ar is examined to find the key determinants of the polarity of plasma jets. The dynamics of the discharge reveal that the radial diffusion discharge is a special phenomenon observed only at the falling edge of the pulses. The radial transport of electrons, which is driven by the radial component of the applied electric field at the falling edge of the pulse, is shown to play an important role in increasing the seed electron density in the surrounding Ar. This result suggests a method to provide seed electrons at atmospheric pressure with a negative discharge. The polarity of the plasma jet is found to be determined by the pulse width rather than the polarity of the applied voltage, as it dictates the relative difference in the intensity of the two discharges in a single pulse, where the stronger discharge in a pulse dominates the behavior of the plasma jet. Accordingly, a method to control the polarity of a plasma jet through varying the pulse width is developed. Since plasma jets of different polarities differ remarkably in terms of their characteristics, the method to control the polarity reported in this paper will be of use for such applications as plasma-enhanced processing of materials and plasma biomedicine.
Publisher: MDPI AG
Date: 11-01-2022
Abstract: Acetylation, a reversible epigenetic process, is implicated in many critical cellular regulatory systems including transcriptional regulation, protein structure, activity, stability, and localization. Lysine acetylation is the most prevalent and intensively investigated among the erse acetylation forms. Owing to the intrinsic connections of acetylation with cell metabolism, acetylation has been associated with metabolic disorders including cancers. Yet, relatively little has been reported on the features of acetylation against the cancer hallmarks, even though this knowledge may help identify appropriate therapeutic strategies or combinatorial modalities for the effective treatment and resolution of malignancies. By examining the available data related to the efficacy of lysine acetylation against tumor cells and elaborating the primary cancer hallmarks and the associated mechanisms to target the specific hallmarks, this review identifies the intrinsic connections between lysine acetylation and cancer hallmarks and proposes novel modalities that can be combined with HDAC inhibitors for cancer treatment with higher efficacy and minimum adverse effects.
Publisher: Wiley
Date: 07-08-2023
Abstract: The development of reliable, cost‐effective molecular detection at the attomolar level on analyte‐immobilizing surfaces fabricated without lithographic patterning remains a major challenge in chemical sensing technology. This issue is addressed using custom‐designed adhesive superhydrophobic silicon nanograss surfaces produced via plasma etching. When applied to ultrasensitive surface‐enhanced Raman scattering, the nanograss surface enables effective immobilization of water droplets containing Ag nanoparticles and R6G target molecules. Upon water evaporation, the R6G analytes are confined at the edge of the self‐organized coffee‐ring‐like stains with the plasmonic hot spots of the Ag nanoparticles, thus providing a reliable Raman scattering platform for detecting trace analytes. Even at an ultralow concentration of 10 −16 m , the corresponding relative standard deviation is 17.57%. A novel plasma‐enabled approach for precise interface nanostructuring, potentially leading to unprecedented capabilities in molecular‐level sensing technologies, is presented.
Publisher: Elsevier BV
Date: 11-2018
Publisher: World Scientific Pub Co Pte Lt
Date: 29-09-2015
DOI: 10.1142/S179360471550054X
Abstract: A low-frequency (460 kHz), low-pressure, thermally non-equilibrium, high-density inductively coupled plasma (ICP) has been used to synthesize a novel, advanced photovoltaic material suitable for fabrication of third-generation solar cells. Silicon quantum dots (SQDs) embedded in an amorphous silicon carbide matrix were prepared at a very low substrate temperature of approximately 200°C without any hydrogen dilution. The effect of the radio-frequency (RF) power of the plasma discharge on the morphology and structure of the embedded quantum dots was studied. A brief discussion on the possible mechanisms of the quantum dot formation in the ICP is presented. This study is relevant to third-generation photovoltaic solar cells.
Publisher: AIP Publishing
Date: 08-01-2016
DOI: 10.1063/1.4939645
Abstract: We report on the effective enhancement and tuning of photoluminescence (PL) by combining vertical graphene nanoflakes (VGs) and carbon nanotips (CNTPs). The VGs are grown on the vertical CNTPs by hot filament chemical vapor deposition in the methane environment, where the CNTPs are synthesized on silicon substrates by CH4-H2-N2 plasma-enhanced hot filament chemical vapor deposition. The results of field emission scanning electron microscopy, transmission electron microscopy, micro-Raman spectroscopy, and X-ray photoelectron spectroscopy indicate that the VGs can be grown on the CNTP and silicon substrate surfaces with the orientation perpendicular to the surfaces of CNTPs and silicon substrates. The PL properties of VG, CNTP, and CNTP-VG structures are studied using a 325 nm line of He-Cd laser as the excitation source. The PL results indicate that the PL of VGs is enhanced by the CNTPs due to the increasing density of PL emitters, while the PL properties of the nanohybrid system can be tuned. Furthermore, the potential applications of CNTP-VG structures in optoelectronic devices are analyzed. These results contribute to the design of functional graphene-based materials and the development of next-generation optoelectronic devices.
Publisher: AIP Publishing
Date: 06-2009
DOI: 10.1063/1.3148667
Abstract: Superhydrophobic amorphous carbon/carbon nanotube nanocomposites are fabricated by plasma immersion ion implantation with carbon nanotube forests as a template. The microstructure of the fabricated nanocomposites shows arrays of carbon nanotubes capped with amorphous carbon nanoparticles. Contact angle measurements show that both advancing and receding angles close to 180° can be achieved on the nanocomposites. The fabrication here does not require patterning of carbon nanotubes or deposition of conformal coatings with low surface energy, which are usually involved in conventional approaches for superhydrophobic surfaces. The relationship between the observed superhydrophobicity and the unique microstructure of the nanocomposites is discussed.
Publisher: AIP Publishing
Date: 09-2018
DOI: 10.1063/1.5031445
Publisher: AIP Publishing
Date: 15-09-2005
DOI: 10.1063/1.2040000
Abstract: Three-dimensional topography of microscopic ion fluxes in the reactive hydrocarbon-based plasma-aided nanofabrication of ordered arrays of vertically aligned single-crystalline carbon nanotip microemitter structures is simulated by using a Monte Carlo technique. The in idual ion trajectories are computed by integrating the ion equations of motion in the electrostatic field created by a biased nanostructured substrate. It is shown that the ion flux focusing onto carbon nanotips is more efficient under the conditions of low potential drop Us across the near-substrate plasma sheath. Under low-Us conditions, the ion current density onto the surface of in idual nanotips is higher for higher-aspect-ratio nanotips and can exceed the mean ion current density onto the entire nanopattern in up to approximately five times. This effect becomes less pronounced with increasing the substrate bias, with the mean relative enhancement of the ion current density ξi not exceeding ∼1.7. The value of ξi is higher in denser plasmas and behaves differently with the electron temperature Te depending on the substrate bias. When the substrate bias is low, ξi decreases with Te, with the opposite tendency under higher-Us conditions. The results are relevant to the plasma-enhanced chemical-vapor deposition of ordered large-area nanopatterns of vertically aligned carbon nanotips, nanofibers, and nanopyramidal microemitter structures for flat-panel display applications.
Publisher: Elsevier BV
Date: 03-2019
DOI: 10.1016/J.ACTBIO.2018.12.024
Abstract: The most common malignancy in women, breast cancer remains a major medical challenge that affects the life of thousands of patients every year. With recognized benefits to body image and self-esteem, the use of synthetic mammary implants for elective cosmetic augmentation and post-mastectomy reconstruction continues to increase. Higher breast implant use leads to an increased occurrence of implant-related complications associated with implant leakage and rupture, capsular contracture, necrosis and infections, which include delayed healing, pain, poor aesthetic outcomes and the need for revision surgeries. Along with the health status of the implant recipient and the skill of the surgeon, the properties of the implant determine the likelihood of implant-related complications and, in doing so, specific patient outcomes. This paper will review the challenges associated with the use of silicone, saline and "gummy bear" implants in view of their application in patients recovering from breast cancer-related mastectomy, and investigate the opportunities presented by advanced functional nanomaterials in meeting these challenges and potentially opening new dimensions for breast reconstruction. STATEMENT OF SIGNIFICANCE: Breast cancer is a significant cause of morbidity and mortality in women worldwide, which is difficult to prevent or predict, and its treatment carries long-term physiological and psychological consequences. Post-mastectomy breast reconstruction addresses the cosmetic aspect of cancer treatment. Yet, drawbacks of current implants contribute to the development of implant-associated complications, which may lead to prolonged patient care, pain and loss of function. Nanomaterials can help resolve the intrinsic biomechanical mismatch between implant and tissues, enhance mechanical properties of soft implantable materials, and provide an alternative avenue for controlled drug delivery. Here, we explore advances in the use of functionalized nanomaterials to enhance the properties of breast implants, with representative ex les that highlight the utility of nanomaterials in addressing key challenges associated with breast reconstruction.
Publisher: Elsevier BV
Date: 2021
Publisher: American Chemical Society (ACS)
Date: 19-01-2016
Publisher: Elsevier BV
Date: 11-2021
Publisher: Wiley
Date: 24-06-2019
Abstract: The development of new battery technology that utilizes abundant electrode materials that are environmentally benign is an important area of research. To alleviate the reliance on Li-ion batteries new energy storage mechanisms are urgently needed. To address these issues, MnO
Publisher: Springer Science and Business Media LLC
Date: 12-1994
DOI: 10.1007/BF01313352
Publisher: Wiley
Date: 09-03-2009
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0TA02121K
Abstract: Using eco-friendly water-based in situ sprouting, 2M (M = Ni, Co) selenide nanosheets are fabricated. The 2M selenide exhibits high HER (24 mV at j 10 ) and OER (346 mV at j 400 ) performances, including a low cell overpotential of 1.69 V at j 100 .
Publisher: AIP Publishing
Date: 03-2007
DOI: 10.1063/1.2480494
Abstract: Uniformity of postprocessing of large-area, dense nanostructure arrays is currently one of the greatest challenges in nanoscience and nanofabrication. One of the major issues is to achieve a high level of control in specie fluxes to specific surface areas of the nanostructures. As suggested by the numerical experiments in this work, this goal can be achieved by manipulating microscopic ion fluxes by varying the plasma sheath and nanorod array parameters. The dynamics of ion-assisted deposition of functional monolayer coatings onto two-dimensional carbon nanorod arrays in a hydrogen plasma is simulated by using a multiscale hybrid numerical simulation. The numerical results show evidence of a strong correlation between the aspect ratios and nanopattern positioning of the nanorods, plasma sheath width, and densities and distributions of microscopic ion fluxes. When the spacing between the nanorods and/or their aspect ratios are larger, and/or the plasma sheath is wider, the density of microscopic ion current flowing to each of the in idual nanorods increases, thus reducing the time required to apply a functional monolayer coating down to 11s for a 7-μm-wide sheath, and to 5s for a 50-μm-wide sheath. The computed monolayer coating development time is consistent with previous experimental reports on plasma-assisted functionalization of related carbon nanostructures [B. N. Khare et al., Appl. Phys. Lett. 81, 5237 (2002)]. The results are generic in that they can be applied to a broader range of plasma-based processes and nanostructures, and contribute to the development of deterministic strategies of postprocessing and functionalization of various nanoarrays for nanoelectronic, biomedical, and other emerging applications.
Publisher: Elsevier BV
Date: 2021
Publisher: American Chemical Society (ACS)
Date: 07-03-2023
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1TA00372K
Abstract: A double-layered trimetallic phosphide of Ni 12 P 5 –Fe 2 P–NbP is engineered on plasma-treated nickel foam, and its overpotentials for the HER and OER are only 265 and 330 mV at j 400 respectively, as well as showing a low cell voltage of 1.65 V at j 100 .
Publisher: AIP Publishing
Date: 08-2008
DOI: 10.1063/1.2963694
Abstract: This article reports on the low-temperature inductively coupled plasma-enabled synthesis of ultralong (up to several millimeters in length) SiO2 nanowires, which were otherwise impossible to synthesize without the presence of a plasma. Depending on the process conditions, the nanowires feature straight, helical, or branched morphologies. The nanowires are amorphous, with a near-stoichiometric elemental composition ([O]/[Si]=2.09) and are very uniform throughout their length. The role of the ionized gas environment is discussed and the growth mechanism is proposed. These nanowires are particularly promising for nanophotonic applications where long-distance and channelled light transmission and polarization control are required.
Publisher: Springer Science and Business Media LLC
Date: 04-04-0025
DOI: 10.1038/S41598-017-13172-Y
Abstract: Lead (Pb) free non-toxic perovskite solar cells have become more important in the commercialization of the photovoltaic devices. In this study the structural, electronic, optical and mechanical properties of Pb-free inorganic metal halide cubic perovskites CsBX 3 (B = Sn, Ge X = I, Br, Cl) for perovskite solar cells are simulated using first-principles Density Functional Theory (DFT). These compounds are semiconductors with direct band gap energy and mechanically stable. Results suggest that the materials have high absorption coefficient, low reflectivity and high optical conductivity with potential application in solar cells and other optoelectronic energy devices. On the basis of the optical properties, one can expect that the Germanium (Ge) would be a better replacement of Pb as Ge containing compounds have higher optical absorption and optical conductivity than that of Pb containing compounds. A combinational analysis of the electronic, optical and mechanical properties of the compounds suggests that CsGeI 3 based perovskite is the best Pb-free inorganic metal halide semiconductor for the solar cell application. However, the compound with solid solution of CsGe(I 0.7 Br 0.3 ) 3 is found to be mechanically more ductile than CsGeI 3 . This study will also guide to obtain Pb-free organic perovskites for optoelectronic devices.
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3CC00282A
Abstract: An atmospheric microplasma jet produces three-dimensional (3D) microfluidic channels on dense arrays of vertically aligned carbon nanotubes, which confines Au nanodot aqueous solution. The resulting hybrid 3D nanostructure is exploited as an effective microscopic area-selective sensing platform based on surface-enhanced Raman scattering.
Publisher: AIP Publishing
Date: 27-03-2014
DOI: 10.1063/1.4869435
Abstract: Phase-selective synthesis of copper oxide nanowires is warranted by several applications, yet it remains challenging because of the narrow windows of the suitable temperature and precursor gas composition in thermal processes. Here, we report on the room-temperature synthesis of small-diameter, large-area, uniform, and phase-pure Cu2O nanowires by exposing copper films to a custom-designed low-pressure, thermally non-equilibrium, high-density (typically, the electron number density is in the range of 1011–1013 cm−3) inductively coupled plasmas. The mechanism of the plasma-enabled phase selectivity is proposed. The gas sensors based on the synthesized Cu2O nanowires feature fast response and recovery for the low-temperature (∼140 °C) detection of methane gas in comparison with polycrystalline Cu2O thin film-based gas sensors. Specifically, at a methane concentration of 4%, the response and the recovery times of the Cu2O nanowire-based gas sensors are 125 and 147 s, respectively. The Cu2O nanowire-based gas sensors have a potential for applications in the environmental monitoring, chemical industry, mining industry, and several other emerging areas.
Publisher: American Chemical Society (ACS)
Date: 20-06-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1NR00317H
Abstract: A MOF-derived CoPO hollow polyhedron structure is designed by simultaneous oxidation hosphatization processes during Ar–N 2 RF plasma discharge.
Publisher: Elsevier BV
Date: 02-2016
Publisher: American Scientific Publishers
Date: 12-2015
Abstract: Mankind faces several global challenges such as chronic and acute hunger, global poverty, energy deficiency and environment conservation. Common biotechnologies based on batch, fluidbed and other similar processes are now extensively used for the production of a wide range of products such as antibiotics, biofuels, cultured and fermented food products. Unfortunately, these processes suffer from low efficiency, high energy demand, low controllability and rapid biocatalyst degradation by microbiological attack, and thus still are not capable of seriously addressing the global hunger and energy deficiency challenges. Moreover, sustainable future technologies require minimizing the environmental impact of toxic by-products by implementing the "life produces organic matter, organic matter sustains life" principle. Nanostructure-based biotechnology is one of the most promising approaches that can help to solve these challenges. In this work we briefly review the unique features of the carbon-based nanostructured platforms, with some attention paid to other nanomaterials. We discuss the main building blocks and processes to design and fabricate novel platforms, with a focus on dense arrays of the vertically-aligned nanostructures, mainly carbon nanotubes and graphene. Advantages and disadvantages of these systems are considered.
Publisher: Wiley
Date: 1995
Publisher: AIP Publishing
Date: 10-2018
DOI: 10.1063/1.5052133
Abstract: Plasma plumes have found a wide range of applications over the recent decade, stimulating studies of characteristics of plasma plumes generated under different conditions. Regardless of whether they propagate within a dielectric tube or different shielding gases, the behavior of these plumes will be affected by the boundary condition of the plume. Yet, at present, little is known about the behavior of plasma plumes of different polarities, especially negative plasma plumes, when propagating under different boundary conditions. To bridge this gap, in this paper, the characteristics of positive and negative plasma plumes propagating within a quartz tube, ambient Ar, and air are studied. The results reveal that the behavior of the positive plasma plume is similar under three different boundary conditions. However, this is not the case for the negative plasma plume, the behavior of which differs significantly between the three cases. Numerical simulation suggests that electron loss due to the drift in the radial direction impacts significantly the characteristics of the negative plasma plume.
Publisher: IOP Publishing
Date: 21-02-2020
Publisher: Elsevier BV
Date: 03-2014
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1CE00075F
Abstract: A halogen salt-assisted confined-space CVD method is used for the controllable synthesis of SnS 2 flakes, which are parallel to the substrate and have the characteristics of better crystallinity and fewer S vacancies.
Publisher: AIP Publishing
Date: 15-04-2009
DOI: 10.1063/1.3112025
Abstract: Carbon nanotips have been synthesized from a thin carbon film deposited on silicon by bias-enhanced hot filament chemical vapor deposition under different process parameters. The results of scanning electron microscopy indicate that high-quality carbon nanotips can only be obtained under conditions when the ion flux is effectively drawn from the plasma sustained in a CH4+NH3+H2 gas mixture. It is shown that the morphology of the carbon nanotips can be controlled by varying the process parameters such as the applied bias, gas pressure, and the NH3/H2 mass flow ratios. The nanotip formation process is examined through a model that accounts for surface diffusion, in addition to sputtering and deposition processes included in the existing models. This model makes it possible to explain the major difference in the morphologies of the carbon nanotips formed without and with the aid of the plasma as well as to interpret the changes of their aspect ratio caused by the variation in the ion/gas fluxes. Viable ways to optimize the plasma-based process parameters to synthesize high-quality carbon nanotips are suggested. The results are relevant to the development of advanced plasma-/ion-assisted methods of nanoscale synthesis and processing.
Publisher: Elsevier
Date: 2014
Publisher: AIP Publishing
Date: 07-2009
DOI: 10.1063/1.3168496
Abstract: Carbon nanotips with different structures were synthesized by plasma-enhanced hot filament chemical vapor deposition and plasma-enhanced chemical vapor deposition using different deposition conditions, and they were investigated by scanning electron microscopy and Raman spectroscopy. The results indicate that the photoluminescence background of the Raman spectra is different for different carbon nanotips. Additionally, the Raman spectra of the carbon nanotips synthesized using nitrogen-containing gas precursors show a peak located at about 2120 cm−1 besides the common D and G peaks. The observed difference in the photoluminescence background is related to the growth mechanisms, structural properties, and surface morphology of a-C:H and a-C:H:N nanotips, in particular, the sizes of the emissive tips.
Publisher: American Chemical Society (ACS)
Date: 14-09-2021
Publisher: Elsevier BV
Date: 2021
Publisher: AIP Publishing
Date: 18-12-2017
DOI: 10.1063/1.5008645
Abstract: An effective surface charge removal is critical to erse applications of polymer and other soft organic materials in electrical devices and systems. Here, we report on the application of atmospheric pressure dielectric barrier discharge (AP-DBD) to deposit SiOx thin films to improve the surface charge dissipation on an epoxy resin surface. The SiOx nanofilms are formed at atmospheric pressure, with the replacement of organic groups (C-H, C=O and C=C) with inorganic groups (Si-O-Si and Si-OH) within the thin surface layer. After the plasma deposition, the initial surface charge decreased by 12% and the surface charge dissipation was accelerated. The flashover voltage which characterizes the insulation property of the epoxy resin is increased by 42%. These improvements are attributed to the lower density of shallow charge traps introduced by SiOx film deposition, which also corresponds to the surface conductivity increase. These results suggest that the SiOx deposition by AP-DBD is promising to accelerate surface charge dissipation. This method is generic, applicable for other types of precursors and may open new avenues for the development of next-generation organic-inorganic insulation materials with customized charge dissipation properties.
Publisher: Wiley
Date: 04-05-2020
Publisher: Wiley
Date: 16-02-2022
Abstract: Nitrogen‐based crop fertilizers are the most important industrial chemicals supporting the global food supply. Plasma‐water‐based nitrogen fixation (PWBNF) provides a clean, sustainable, and flexible alternative, which is amenable for decentralized, small‐to‐medium‐scale production systems. This process is based on the targeted activation of N 2 or air molecules by plasmas. Plasma can interact with water molecules, water droplets, and water layers through the plasma physical and chemical mechanisms. This review summarizes the current state of the art of PWBNF and provides insights into the effective mechanisms for the synthesis of NH 3 , NO 2 − and NO 3 − in highly reactive plasma environments. The opportunities and challenges for this plasma‐enabled approach are identified to guide the development of sustainable nitrogen fixation technology.
Publisher: American Chemical Society (ACS)
Date: 15-06-2020
Publisher: Elsevier BV
Date: 05-2022
Publisher: Elsevier BV
Date: 09-2018
Publisher: Wiley
Date: 21-02-2018
Publisher: MDPI AG
Date: 25-06-2014
DOI: 10.3390/MA7074896
Publisher: Elsevier BV
Date: 2021
Publisher: American Chemical Society (ACS)
Date: 22-01-2013
DOI: 10.1021/JA3110279
Abstract: A multiscale, multiphase thermokinetic model is used to show the effective control of the growth orientation of thin Si NWs for nanoelectronic devices enabled by nanoscale plasma chemistry. It is shown that very thin Si NWs with [110] growth direction can nucleate at much lower process temperatures and pressures compared to thermal chemical vapor deposition where [111]-directed Si NWs are predominantly grown. These findings explain a host of experimental results and offer the possibility of energy- and matter-efficient, size- and orientation-controlled growth of [110] Si NWs for next-generation nanodevices.
Publisher: Springer Science and Business Media LLC
Date: 06-2021
Publisher: IOP Publishing
Date: 06-08-2019
Publisher: Elsevier BV
Date: 12-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2RA00414C
Abstract: This work summarizes that RbSnX 3 (X = Cl, Br, I) exhibits remarkable ductility and absorption in the ultraviolet (UV) region of the electromagnetic spectrum compared to those of CsBX 3 (B = Ge, Sn, Pb X = Cl, Br, I) metal halide perovskites.
Publisher: Elsevier BV
Date: 07-2014
Publisher: Springer Science and Business Media LLC
Date: 05-02-2013
DOI: 10.1038/SREP01221
Publisher: American Chemical Society (ACS)
Date: 28-05-2020
Publisher: MDPI AG
Date: 02-10-2019
DOI: 10.3390/NANO9101405
Abstract: To unravel the influence of the temperature and plasma species on the growth of single-crystalline metal oxide nanostructures, zinc, iron, and copper foils were used as substrates for the study of nanostructure synthesis in the glow discharge of the mixture of oxygen and argon gases by a custom-made plasma-enhanced horizontal tube furnace deposition system. The morphology and microstructure of the resulting metal oxide nanomaterials were controlled by changing the reaction temperature from 300 to 600 °C. Experimentally, we confirmed that single-crystalline zinc oxide, copper oxide, and iron oxide nanostructures with tunable morphologies (including nanowires, nanobelts, etc.) can be successfully synthesized via such procedure. A plausible growth mechanism for the synthesis of metal oxide nanostructures under the plasma-based process is proposed and supported by the nanostructure growth modelling. The results of this work are generic, confirmed on three different types of materials, and can be applied for the synthesis of a broader range of metal oxide nanostructures.
Publisher: Springer Science and Business Media LLC
Date: 17-04-2018
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6RA17940A
Abstract: A simple and efficient method for synthesizing complex graphene-inspired BNCO nanoflakes by plasma-enhanced hot filament chemical vapour deposition using B 4 C as a precursor and N 2 /H 2 reactive gases is reported.
Publisher: AIP Publishing
Date: 09-2010
DOI: 10.1063/1.3482212
Abstract: We report on the application low-temperature plasmas for roughening Si surfaces which is becoming increasingly important for a number of applications ranging from Si quantum dots to cell and protein attachment for devices such as “laboratory on a chip” and sensors. It is a requirement that Si surface roughening is scalable and is a single-step process. It is shown that the removal of naturally forming SiO2 can be used to assist in the roughening of the surface using a low-temperature plasma-based etching approach, similar to the commonly used in semiconductor micromanufacturing. It is demonstrated that the selectivity of SiO2/Si etching can be easily controlled by tuning the plasma power, working gas pressure, and other discharge parameters. The achieved selectivity ranges from 0.4 to 25.2 thus providing an effective means for the control of surface roughness of Si during the oxide layer removal, which is required for many advance applications in bio- and nanotechnology.
Publisher: American Physical Society (APS)
Date: 20-12-2011
Publisher: AIP Publishing
Date: 26-08-2013
DOI: 10.1063/1.4820148
Abstract: Effects of surrounding gases on the propagation of room-temperature atmospheric-pressure plasma jets are reported. A highly unusual feather-like plasma plume is observed only when N2 is used as surrounding gas. The He concentration on the axis at the starting point of the feather-like plume is ∼0.85 of the maximum value and is independent on the He flow rates. High-speed optical imaging reveals that dim diffuse plasmas emerge just behind the bright head of the plasma bullet at the starting point of the feather-like plume. These results help tailoring surface exposure in emerging applications of plasma jets in medicine and nanotechnology.
Publisher: MDPI AG
Date: 06-02-2022
DOI: 10.3390/EN15031191
Abstract: Ti3C2Tx-based aerogels have attracted widespread attention for three-dimensional porous structures, which are promising to realize high-rate energy storage. However, disordered Ti3C2Tx aerogels with highly tortuous porosity fabricated by conventional unidirectional freeze-casting substantially increase ion diffusion lengths and hinder electrolyte ions transport. Herein we demonstrate a new bidirectional ice-templated approach to synthesize porous ordered Ti3C2Tx aerogel with straight and aligned channels, straight and short ion diffusion pathways, leading to better ion accessibility. The aligned Ti3C2Tx aerogel exhibits the high specific capacitance of 345 F g−1 at 20 mV s−1 and rate capability of 52.2% from 10 to 5000 mV s−1. The specific capacitance is insensitive of mass loadings even at 10 mg cm−2 and an excellent power density of 137.3 mW cm–2 is obtained in symmetric supercapacitors. The electrochemical properties of Ti3C2Tx aerogel supercapacitors at sub-zero (to −30 °C) temperatures are reported for the first time. The aligned Ti3C2Tx aerogel delivers temperature-independent rate performance and high capacitance retention (73% at 50 mV s−1 from 25 to −30 °C) due to the unique structure with metallic conductivity.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-2012
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5NR06365E
Abstract: Atomically thin graphene holds exceptional promise to enable new functionalities and drastically improve performance of electronic, energy, sensing, and bio-medical devices. One of the most promising approaches to device-compatible graphene synthesis is chemical vapour deposition on a copper catalyst this technique however is limited by very high temperatures (∼900 °C) and a lack of control as well as post-growth separation from the catalyst. We demonstrate and explain how, through the use of a plasma, a graphene film containing single layer graphene can be grown at temperature as low as 220 °C, the process can be controlled and an instant and water-mediated decoupling mechanism is realised. Potential use of our films in flexible transparent conductive films, electrical devices and magneto-electronics is demonstrated. Considering the benefits of catalyst reuse, energy efficiency, simplicity, and environmental friendliness, we present this versatile plasma process as a viable alternative to many existing graphene production approaches.
Publisher: Wiley
Date: 07-2007
Abstract: The plasma‐assisted RF sputtering deposition of a biocompatible, functionally graded calcium phosphate bioceramic on a Ti6Al4 V orthopedic alloy is reported. The chemical composition and presence of hydroxyapatite (HA), CaTiO 3 , and CaO mineral phases can be effectively controlled by the process parameters. At higher DC biases, the ratio [Ca]/[P] and the amount of CaO increase, whereas the HA content decreases. Optical emission spectroscopy suggests that CaO + is the dominant species that responds to negative DC bias and controls calcium content. Biocompatibility tests in simulated body fluid confirm a positive biomimetic response evidenced by in‐growth of an apatite layer after 24 h of immersion.
Publisher: AIP Publishing
Date: 18-03-2013
DOI: 10.1063/1.4798535
Abstract: The effect of plasmon oscillations on the DC tunnel current in a gold nanoisland thin film (GNITF) is investigated using low intensity P ∼ 1 W/cm2 continuous wave lasers. While DC voltages (1–150 V) were applied to the GNITF, it was irradiated with lasers at different wavelengths (λ = 473, 532, and 633 nm). Because of plasmon oscillations, the tunnel current increased. It is found that the tunnel current enhancement is mainly due to the thermal effect of plasmon oscillations rather than other plasmonic effects. The results are highly relevant to applications of plasmonic effects in opto-electronic devices.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9NR04951G
Abstract: Oxidative stress in cells caused by the accumulation of reactive oxygen species (ROS) is a common cause of cell function degeneration, cell death and various diseases. Efficient, robust and inexpensive nanoparticles (nanoenzymes) capable of scavenging/detoxifying ROS even in harsh environments are attracting strong interest. Prussian blue analogues (PBAs), a prominent group of metalorganic nanoparticles (NPs) with the same cyanometalate structure as the traditional and commonly used Prussian blue (PB), have long been envisaged to mimic enzyme activities for ROS scavenging. However, their biological toxicity, especially potential effects on living beings during practical application, has not yet been fully investigated. Here we reveal the enzyme-like activity of FeCo-PBA NPs, and for the first time investigate the effects of FeCo-PBA on cell viability and growth. We elucidate the effect of the nanoenzyme on the ethanol-production efficacy of a typical model organism, the engineered industrial strain Saccharomyces cerevisiae. We further demonstrate that FeCo-PBA NPs have almost no cytotoxicity on the cells over a broad dosage range (0-100 μg mL
Publisher: Elsevier BV
Date: 09-2009
Publisher: AIP Publishing
Date: 02-06-2008
DOI: 10.1063/1.2928219
Abstract: An effective technique to improve the precision and throughput of energetic ion condensation through dielectric nanoporous templates and reduce nanopore clogging by using finely tuned pulsed bias is proposed. Multiscale numerical simulations of ion deposition show the possibility of controlling the dynamic charge balance on the upper template’s surface to minimize ion deposition on nanopore sidewalls and to deposit ions selectively on the substrate surface in contact with the pore opening. In this way, the shapes of nanodots in template-assisted nanoarray fabrication can be effectively controlled. The results are applicable to various processes involving porous dielectric nanomaterials and dense nanoarrays.
Publisher: American Chemical Society (ACS)
Date: 06-12-2020
Abstract: Herein, we report the cartilage tissue engineering application of nanographene oxide (NGO)-reinforced gelatin hydrogel fabricated by utilizing a microplasma-assisted cross-linking method. NGO sheets with surface functionalities were introduced to enhance the mechanical and biomedical properties of gelatin-based hydrogels. Highly energetic reactive radicals were generated from the nonthermal plasma (NTP), which is used to facilitate the cross-linking and polymerization during the polymeric hydrogel fabrication. The NTP treatment substantially reinforced a small amount (1 wt %) of NGO into the gelatin hydrogel. Systematic material characterization thus shows that the fabricated hydrogel possessed unique properties such as moderate surface roughness and adhesiveness, suitable pores sizes, temperature-dependent viscoelasticity, and controllable degradability. In vitro studies demonstrated that the as-fabricated hydrogel exhibited excellent cell-material interactions with SW 1353 cells, bone marrow-derived mesenchymal stem cells, and a rat chondrocyte cell line, thereby exhibiting appropriate cytocompatibility for cartilage tissue engineering applications. Furthermore, an in vivo study indicated that the formation of a healthy hyaline cartilage after the microfracture was enhanced by the fabricated hydrogel implant, offering a potential biocompatible platform for microfracture-based cartilage reconstructive surgery.
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C4NR07351G
Abstract: Single-molecule-detection, selectivity, broad-range detection and biocompatibility are achieved using nanoporous diamond-like carbon coated oxide membranes.
Publisher: Elsevier BV
Date: 02-2022
Publisher: IOP Publishing
Date: 18-11-2021
Abstract: In recent years, two-dimensional materials have received more and more attention in the development of semiconductor devices, and their practical applications in optoelectronic devices have also developed rapidly. However, there are still some factors that limit the performance of two-dimensional semiconductor material devices, and one of the most important is Ohmic contact. Here, we elaborate on a variety of approaches to achieve Ohmic contacts on two-dimensional materials and reveal their physical mechanisms. For the work function mismatch problem, we summarize the comparison of barrier heights between different metals and 2D semiconductors. We also examine different methods to solve the problem of Fermi level pinning. For the novel 2D metal-semiconductor contact methods, we analyse their effects on reducing contact resistance from two different perspectives: homojunction and heterojunction. Finally, the challenges of 2D semiconductors in achieving Ohmic contacts are outlined.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8RA08920E
Abstract: New surface coating pathway by plasma-enabled surface-catalyzed reaction, offering control of surface chemistry, wettability and roughness.
Publisher: IOP Publishing
Date: 14-09-2018
Abstract: Heterostructures of two-dimensional (2D) transition metal dichalcogenides (TMDs) offer attractive prospects for practical applications by combining unique physical properties that are distinct from those of traditional structures. In this paper, we demonstrate a three-stage chemical vapor deposition method for the growth of bilayer MoS
Publisher: Wiley
Date: 07-2013
Abstract: Molecular doping and detection are at the forefront of graphene research, a topic of great interest in physical and materials science. Molecules adsorb strongly on graphene, leading to a change in electrical conductivity at room temperature. However, a common impediment for practical applications reported by all studies to date is the excessively slow rate of desorption of important reactive gases such as ammonia and nitrogen dioxide. Annealing at high temperatures, or exposure to strong ultraviolet light under vacuum, is employed to facilitate desorption of these gases. In this article, the molecules adsorbed on graphene nanoflakes and on chemically derived graphene-nanomesh flakes are displaced rapidly at room temperature in air by the use of gaseous polar molecules such as water and ethanol. The mechanism for desorption is proposed to arise from the electrostatic forces exerted by the polar molecules, which decouples the overlap between substrate defect states, molecule states, and graphene states near the Fermi level. Using chemiresistors prepared from water-based dispersions of single-layer graphene on mesoporous alumina membranes, the study further shows that the edges of the graphene flakes (showing p-type responses to NO₂ and NH₃) and the edges of graphene nanomesh structures (showing n-type responses to NO₂ and NH₃) have enhanced sensitivity. The measured responses towards gases are comparable to or better than those which have been obtained using devices that are more sophisticated. The higher sensitivity and rapid regeneration of the sensor at room temperature provides a clear advancement towards practical molecule detection using graphene-based materials.
Publisher: Springer Science and Business Media LLC
Date: 28-04-2020
Publisher: American Chemical Society (ACS)
Date: 07-11-2008
DOI: 10.1021/CG8008283
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2008
Publisher: AIP Publishing
Date: 04-2013
DOI: 10.1063/1.4798527
Abstract: Textured silicon surfaces are widely used in manufacturing of solar cells due to increasing the light absorption probability and also the antireflection properties. However, these Si surfaces have a high density of surface defects that need to be passivated. In this study, the effect of the microscopic surface texture on the plasma surface passivation of solar cells is investigated. The movement of 105 H+ ions in the texture-modified plasma sheath is studied by Monte Carlo numerical simulation. The hydrogen ions are driven by the combined electric field of the plasma sheath and the textured surface. The ion dynamics is simulated, and the relative ion distribution over the textured substrate is presented. This distribution can be used to interpret the quality of the Si dangling bonds saturation and consequently, the direct plasma surface passivation.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2008
Publisher: Wiley
Date: 09-05-2018
Publisher: AIP Publishing
Date: 21-05-2012
DOI: 10.1063/1.4720513
Abstract: The effect of plasmon oscillations, induced by pulsed laser irradiation, on the DC tunnel current between islands in a discontinuous thin gold film is studied. The tunnel current is found to be strongly enhanced by partial rectification of the plasmon-induced AC tunnel currents flowing between adjacent gold islands. The DC tunnel current enhancement is found to increase approximately linearly with the laser intensity and the applied DC bias voltage. The experimental data can be well described by an electron tunnelling model which takes the plasmon-induced AC voltage into account. Thermal heating seems not to contribute to the tunnel current enhancement.
Publisher: Wiley
Date: 08-07-2019
Publisher: IOP Publishing
Date: 04-1994
Publisher: Elsevier BV
Date: 03-2022
Publisher: Wiley
Date: 24-09-2022
Abstract: Integrated polarization‐sensitive photodetectors fabricated by geometric anisotropic 2D materials have become attractive in recent years. In this work, the successful construction of self‐driven and polarization‐sensitive photodetectors based on GaTe/MoS 2 p–n van der Waals (vdW) heterojunction is demonstrated by mechanical exfoliation and dry transfer methods. The fabricated GaTe/MoS 2 vdW heterojunctions show ambipolar behavior, and the highest rectification ratio can reach 93.4. The highest responsivity under 532 nm illumination reaches 145 mA W −1 and the response time is less than 10 ms. Moreover, the photocurrent polarization of the fabricated GaTe/MoS 2 photodetectors manifests in fourfold anisotropy with a high polarization ratio of 2.9, which can be ascribed to the highly anisotropic monoclinic structure of layered m‐GaTe. This finding thus offers more information and creates new opportunities about how to fabricate integrated polarization‐sensitive photodetectors.
Publisher: Elsevier BV
Date: 09-2017
Publisher: American Chemical Society (ACS)
Date: 12-10-2021
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 1998
DOI: 10.1109/27.659538
Publisher: IOP Publishing
Date: 23-12-2023
Abstract: Epitaxial graphene on SiC is the most promising substrate for the next generation 2D electronics, due to the possibility to fabricate 2D heterostructures directly on it, opening the door to the use of all technological processes developed for silicon electronics. To obtain a suitable material for large scale applications, it is essential to achieve perfect control of size, quality, growth rate and thickness. Here we show that this control on epitaxial graphene can be achieved by exploiting the face-to-face annealing of SiC in ultra-high vacuum. With this method, Si atoms trapped in the narrow space between two SiC wafers at high temperatures contribute to the reduction of the Si sublimation rate, allowing to achieve smooth and virtually defect free single graphene layers. We analyse the products obtained on both on-axis and off-axis 4H-SiC substrates in a wide range of temperatures (1300 °C–1500 °C), determining the growth law with the help of x-ray photoelectron spectroscopy (XPS). Our epitaxial graphene on SiC has terrace widths up to 10 μ m (on-axis) and 500 nm (off-axis) as demonstrated by atomic force microscopy and scanning tunnelling microscopy, while XPS and Raman spectroscopy confirm high purity and crystalline quality.
Publisher: Elsevier BV
Date: 02-2017
Publisher: IOP Publishing
Date: 08-07-2008
DOI: 10.1088/0957-4484/19/33/335703
Abstract: The kinetics of saturation of Ni catalyst nanoparticle patterns of the three different degrees of order, used as a model for the growth of carbon nanotips on Si, is investigated numerically using a complex model that involves surface diffusion and ion motion equations. It is revealed that Ni catalyst patterns of different degrees of order, with Ni nanoparticle sizes up to 12.5 nm, exhibit different kinetics of saturation with carbon on the Si surface. It is shown that in the cases examined (surface coverage in the range of 1-50%, highly disordered Ni patterns) the relative pattern saturation factor calculated as the ratio of average incubation times for the processes conducted in the neutral and ionized gas environments reaches 14 and 3.4 for Ni nanoparticles of 2.5 and 12.5 nm, respectively. In the highly ordered Ni patterns, the relative pattern saturation factor reaches 3 for nanoparticles of 2.5 nm and 2.1 for nanoparticles of 12.5 nm. Thus, more simultaneous saturation of Ni catalyst nanoparticles of sizes in the range up to 12.5 nm, deposited on the Si substrate, can be achieved in the low-temperature plasma environment than with the neutral gas-based process.
Publisher: Elsevier BV
Date: 05-2010
Publisher: Walter de Gruyter GmbH
Date: 2008
Abstract: The paper presents an investigation of self-organizational and -assembly processes of nanostructure growth on surfaces exposed to low-temperature plasmas. We have considered three main growth stages-initial, or sub-monolayer growth stage, separate nanostructure growth stage, and array growth stages with the characteristic sizes of several nm, several tens of nm, and several hundreds of nm, respectively, and have demonstrated, by the experimental data and hybrid multiscale numerical simulations, that the plasma parameters can strongly influence the surface processes and hence the kinetics of self-organization and -assembly. Our results show that plasma-controlled self-organization is a promising way to assemble large regular arrays of nanostructures.
Publisher: Elsevier BV
Date: 10-2005
Publisher: Wiley
Date: 06-05-2016
Publisher: American Chemical Society (ACS)
Date: 08-02-2013
DOI: 10.1021/JZ400092M
Abstract: We report on the chemical synthesis of the arrays of silicon oxide nanodots and their self-organization on the surface via physical processes triggered by surface charges. The method based on chemically active oxygen plasma leads to the rearrangement of nanostructures and eventually to the formation of groups of nanodots. This behavior is explained in terms of the effect of electric field on the kinetics of surface processes. The direct measurements of the electric charges on the surface demonstrate that the charge correlates with the density and arrangement of nanodots within the array. Extensive numerical simulations support the proposed mechanism and prove a critical role of the electric charges in the self-organization. This simple and environment-friendly self-guided process could be used in the chemical synthesis of large arrays of nanodots on semiconducting surfaces for a variety of applications in catalysis, energy conversion and storage, photochemistry, environmental and biosensing, and several others.
Publisher: Elsevier BV
Date: 06-2019
Publisher: Elsevier BV
Date: 08-2009
Publisher: Elsevier BV
Date: 12-1995
Publisher: Elsevier BV
Date: 08-2008
Publisher: World Scientific Pub Co Pte Lt
Date: 12-2010
DOI: 10.1142/S179360471000138X
Abstract: The results on the synthesis, mechanical and electrical properties of carbon microcoils and nanocoils (CMCs, CNCs) synthesized using catalytic CVD and Ni–P and Co–P catalyst alloys, respectively, are reported. SEM analysis reveals that the CMCs and CNCs have unique helical morphologies, and diameters of 5.0–9.0 μm and 450–550 nm, respectively. Moreover, CMCs with flat cross-section can be stretched to 3 times their original coil lengths. Current–voltage characteristics of a single microcoil have also been obtained. It is found that the CMCs have the electrical conductivity between 100 and 160 S/cm, whereas the electrical resistance increases by about 20% during the coil extension. Besides, the microcoils can produce light in vacuum when the test voltage reaches 10 V. The emission intensity increases as the voltage increases. The mechanical and electrical properties of CMCs and CNC make them potentially useful in many applications in micromagnetic sensors, mechanical microsprings and optoelectronics.
Publisher: AIP Publishing
Date: 05-2015
DOI: 10.1063/1.4919732
Abstract: This note reports on a novel method for the rapid reduction of graphene oxide (GO) paper using a glow discharge plasma reactor. Glow discharge is produced and sustained between two parallel-plate graphite electrodes at a pressure of 240 mTorr. By exposing GO paper at the junction of negative-glow and Faraday-dark area for 4 min, the oxygen-containing groups can be effectively removed (C/O ratio increases from 2.6 to 7.9), while the material integrality and flexibility are kept well. Electrochemical measurements demonstrate that the as-obtained reduced GO paper can be potentially used for supercapacitor application.
Publisher: Elsevier BV
Date: 11-2015
Publisher: Elsevier BV
Date: 08-2012
Publisher: IOP Publishing
Date: 27-03-2008
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6RA00405A
Abstract: MnO 2 NPs were decorated on the DBD plasma-functionalized MWCNTs in H 2 O vapor-saturated air for glucose detection.
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C4CS00352G
Abstract: This tutorial review summarizes plasma synthesis of vertically-oriented graphenes, their growth mechanisms and unique properties for energy and environmental applications.
Publisher: American Chemical Society (ACS)
Date: 20-09-2022
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0RE00241K
Abstract: At a time of rapid depletion of oil resources, global food shortages and solid waste problems, it is imperative to encourage research into the use of appropriate pre-treatment techniques using regenerative raw materials such as lignocellulosic biomass.
Publisher: American Vacuum Society
Date: 21-04-2005
DOI: 10.1116/1.1875252
Abstract: Transitions between the two discharge modes in a low-frequency (∼460kHz) inductively coupled plasma sustained by an internal oscillating radio frequency (rf) current sheet are studied. The unidirectional rf current sheet is generated by an internal antenna comprising two orthogonal sets of synphased rf currents driven in alternately reconnected copper litz wires. It is shown that in the low-to-intermediate pressure range the plasma source can be operated in the electrostatic (E) and electromagnetic (H) discharge modes. The brightness of the E-mode argon plasma glow is found remarkably higher than in inductively coupled plasmas with external flat spiral “pancake” coils. The cyclic variations of the input rf power result in pronounced hysteretic variations of the optical emission intensity and main circuit parameters of the plasma source. Under certain conditions, it appears possible to achieve a spontaneous E→H transition (“self-transition”). The observed phenomenon can be attributed to the thermal drift of the plasma parameters due to the overheating of the working gas. The discharge destabilizing factors due to the gas heating and step-wise ionization are also discussed.
Publisher: Elsevier BV
Date: 11-2014
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2CP02795J
Abstract: This article links fundamental mechanisms and macroscopic properties and provides guiding principles for performance optimization to achieve a rational balance between the stability and other critical properties of aqueous electrolytes.
Publisher: Informa UK Limited
Date: 04-2013
Publisher: Elsevier BV
Date: 03-2022
Publisher: AIP Publishing
Date: 13-07-2009
DOI: 10.1063/1.3179557
Abstract: The nucleation-initiated oxidation of a Si surface at very low temperatures in plasmas is demonstrated experimentally, in contrast to the Deal–Grove mechanism, which predicts Si oxidation at a Si/SiO interface and cannot adequately describe the formation of SiO nanodots and oxidation rates at very low (several nanometers) oxide thickness. Based on the experimental results, an alternative oxidation scenario is proposed and supported by multiscale numerical simulations suggesting that saturation of micro- and nanohillocks with oxygen is a trigger mechanism for initiation of Si surface oxidation. This approach is generic and can be applied to describe the kinetics of low-temperature oxidation of other materials.
Publisher: Elsevier BV
Date: 06-2010
Publisher: Springer Science and Business Media LLC
Date: 13-08-2013
DOI: 10.1038/NCOMMS3220
Abstract: Development of technologies for water desalination and purification is critical to meet the global challenges of insufficient water supply and inadequate sanitation, especially for point-of-use applications. Conventional desalination methods are energy and operationally intensive, whereas adsorption-based techniques are simple and easy to use for point-of-use water purification, yet their capacity to remove salts is limited. Here we report that plasma-modified ultralong carbon nanotubes exhibit ultrahigh specific adsorption capacity for salt (exceeding 400% by weight) that is two orders of magnitude higher than that found in the current state-of-the-art activated carbon-based water treatment systems. We exploit this adsorption capacity in ultralong carbon nanotube-based membranes that can remove salt, as well as organic and metal contaminants. These ultralong carbon nanotube-based membranes may lead to next-generation rechargeable, point-of-use potable water purification appliances with superior desalination, disinfection and filtration properties.
Publisher: Oxford University Press (OUP)
Date: 13-10-2014
DOI: 10.1093/CRJ/CLU019
Publisher: AIP Publishing
Date: 29-03-2010
DOI: 10.1063/1.3374324
Abstract: The possibility of independent control of the surface fluxes of energy and hydrogen-containing radicals, thus enabling selective control of the nanostructure heating and passivation, is demonstrated. In situ energy flux measurements reveal that even a small addition of H2 to low-pressure Ar plasmas leads to a dramatic increase in the energy deposition through H recombination on the surface. The heat release is quenched by a sequential addition of a hydrocarbon precursor while the surface passivation remains effective. Such selective control offers an effective mechanism for deterministic control of the growth shape, crystallinity, and density of nanostructures in plasma-aided nanofabrication.
Publisher: Elsevier BV
Date: 10-2009
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9TC01134J
Abstract: Dirac cone in metal-semiquinoid frameworks.
Publisher: Elsevier BV
Date: 03-2014
DOI: 10.1016/J.SCR.2013.11.003
Abstract: An essential step for therapeutic and research applications of stem cells is their ability to differentiate into specific cell types. Neuronal cells are of great interest for medical treatment of neurodegenerative diseases and traumatic injuries of central nervous system (CNS), but efforts to produce these cells have been met with only modest success. In an attempt of finding new approaches, atmospheric-pressure room-temperature microplasma jets (MPJs) are shown to effectively direct in vitro differentiation of neural stem cells (NSCs) predominantly into neuronal lineage. Murine neural stem cells (C17.2-NSCs) treated with MPJs exhibit rapid proliferation and differentiation with longer neurites and cell bodies eventually forming neuronal networks. MPJs regulate ~75% of NSCs to differentiate into neurons, which is a higher efficiency compared to common protein- and growth factors-based differentiation. NSCs exposure to quantized and transient (~150 ns) micro-plasma bullets up-regulates expression of different cell lineage markers as β-Tubulin III (for neurons) and O4 (for oligodendrocytes), while the expression of GFAP (for astrocytes) remains unchanged, as evidenced by quantitative PCR, immunofluorescence microscopy and Western Blot assay. It is shown that the plasma-increased nitric oxide (NO) production is a factor in the fate choice and differentiation of NSCs followed by axonal growth. The differentiated NSC cells matured and produced mostly cholinergic and motor neuronal progeny. It is also demonstrated that exposure of primary rat NSCs to the microplasma leads to quite similar differentiation effects. This suggests that the observed effect may potentially be generic and applicable to other types of neural progenitor cells. The application of this new in vitro strategy to selectively differentiate NSCs into neurons represents a step towards reproducible and efficient production of the desired NSC derivatives.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-2014
Publisher: Elsevier BV
Date: 06-2009
Publisher: Springer Science and Business Media LLC
Date: 27-01-2016
DOI: 10.1038/SREP19945
Abstract: Transition from multi-layer to monolayer and sub-monolayer thickness leads to the many exotic properties and distinctive applications of two-dimensional (2D) MoS 2 . This transition requires atomic-layer-precision thinning of bulk MoS 2 without damaging the remaining layers, which presently remains elusive. Here we report a soft, selective and high-throughput atomic-layer-precision etching of MoS 2 in SF 6 + N 2 plasmas with low-energy ( .4 eV) electrons and minimized ion-bombardment-related damage. Equal numbers of MoS 2 layers are removed uniformly across domains with vastly different initial thickness, without affecting the underlying SiO 2 substrate and the remaining MoS 2 layers. The etching rates can be tuned to achieve complete MoS 2 removal and any desired number of MoS 2 layers including monolayer. Layer-dependent vibrational and photoluminescence spectra of the etched MoS 2 are also demonstrated. This soft plasma etching technique is versatile, scalable, compatible with the semiconductor manufacturing processes and may be applicable for a broader range of 2D materials and intended device applications.
Publisher: Wiley
Date: 10-09-2015
Abstract: By increasing the density of exposed active edges, the perpendicularly oriented structure of MoSe2 nanosheets facilitates ion/electrolyte transport at the electrode interface and minimizes the restacking of nanosheets, while the graphene improves the electrical contact between the catalyst and the electrode. This makes the MoSe2 /graphene hybrid perfect as a catalyst in the hydrogen evolution reaction (HER). It shows a greatly improved catalytic activity compared with bare MoSe2 nanosheets.
Publisher: IOP Publishing
Date: 21-11-2019
Publisher: IOP Publishing
Date: 08-03-2022
Abstract: Two-dimensional (2D) materials including black phosphorus (BP) have been extensively investigated because of their exotic physical properties and potential applications in nanoelectronics and optoelectronics. Fabricating BP based devices is challenging because BP is extremely sensitive to the external environment, especially to the chemical contamination during the lithography process. The direct evaporation through shadow mask technique is a clean method for lithography-free electrode patterning of 2D materials. Herein, we employ the lithography-free evaporation method for the construction of BP based field-effect transistors and photodetectors and systematically compare their performances with those of BP counterparts fabricated by conventional lithography and transfer electrode methods. The results show that BP devices fabricated by direct evaporation method possess higher mobility, faster response time, and smaller hysteresis than those prepared by the latter two methods. This can be attributed to the clean interface between BP and evaporated-electrodes as well as the lower Schottky barrier height of 20.2 meV, which is given by the temperature-dependent electrical results. Furthermore, the BP photodetectors exhibit a broad-spectrum response and polarization sensitivity. Our work elucidates a universal, low-cost and high-efficiency method to fabricate BP devices for optoelectronic applications.
Publisher: Wiley
Date: 19-08-2014
Publisher: The Optical Society
Date: 08-04-2014
DOI: 10.1364/OL.39.002334
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3NR01735D
Abstract: The multi-modal therapy has superior anti-tumor efficacy to the uni-modal using nanoparticles inducing reactive oxygen species (ROS). The multi-component nature of cold atmospheric plasma (CAP) enables multi-modal excitation with a single treatment.
Publisher: MDPI AG
Date: 20-01-2014
DOI: 10.3390/MA7010563
Publisher: Springer Science and Business Media LLC
Date: 05-02-2019
DOI: 10.1038/S41467-019-08468-8
Abstract: Epitaxial growth of atomically thin two-dimensional crystals such as transition metal dichalcogenides remains challenging, especially for producing large-size transition metal dichalcogenides bilayer crystals featuring high density of states, carrier mobility and stability at room temperature. Here we achieve in epitaxial growth of the second monolayer from the first monolayer by reverse-flow chemical vapor epitaxy and produce high-quality, large-size transition metal dichalcogenides bilayer crystals with high yield, control, and reliability. Customized temperature profiles and reverse gas flow help activate the first layer without introducing new nucleation centers leading to near-defect-free epitaxial growth of the second layer from the existing nucleation centers. A series of bilayer crystals including MoS 2 and WS 2 , ternary Mo 1−x W x S 2 and quaternary Mo 1−x W x S 2(1−y) Se 2y are synthesized with variable structural configurations and tunable electronic and optical properties. The robust, potentially universal approach for the synthesis of large-size transition metal dichalcogenides bilayer single crystals is highly-promising for fundamental studies and technological applications.
Publisher: Springer Science and Business Media LLC
Date: 17-07-2017
DOI: 10.1038/S41598-017-04963-4
Abstract: Cold atmospheric plasma has recently emerged as a simple, low-cost and efficient physical method for inducing significant biological responses in seeds and plants without the use of traditional, potentially environmentally-hazardous chemicals, fungicides or hormones. While the beneficial effects of plasma treatment on seed germination, disease resistance and agricultural output have been reported, the mechanisms that underpin the observed biological responses are yet to be fully described. This study employs Fourier Transform Infrared (FTIR) spectroscopy and emission spectroscopy to capture chemical interactions between plasmas and seed surfaces with the aim to provide a more comprehensive account of plasma−seed interactions. FTIR spectroscopy of the seed surface confirms plasma-induced chemical etching of the surface. The etching facilitates permeation of water into the seed, which is confirmed by water uptake measurements. FTIR of exhaust and emission spectra of discharges show oxygen-containing species known for their ability to stimulate biochemical processes and deactivate pathogenic microorganisms. In addition, water gas, CO 2 , CO and molecules containing −C(CH 3 ) 3 − moieties observed in FTIR spectra of the exhaust gas during plasma treatment may be partly responsible for the plasma chemical etching of seed surface through oxidizing the organic components of the seed coat.
Publisher: AIP Publishing
Date: 11-06-2012
DOI: 10.1063/1.4729053
Publisher: Wiley
Date: 14-05-2014
Abstract: Graphene and carbon nanotubes (CNTs) are attractive electrode materials for supercapacitors. However, challenges such as the substrate-limited growth of CNTs, nanotube bundling in liquid electrolytes, under-utilized basal planes, and stacking of graphene sheets have so far impeded their widespread application. Here we present a hybrid structure formed by the direct growth of CNTs onto vertical graphene nanosheets (VGNS). VGNS are fabricated by a green plasma-assisted method to break down and reconstruct a natural precursor into an ordered graphitic structure. The synergistic combination of CNTs and VGNS overcomes the challenges intrinsic to both materials. The resulting VGNS/CNTs hybrids show a high specific capacitance with good cycling stability. The charge storage is based mainly on the non-Faradaic mechanism. In addition, a series of optimization experiments were conducted to reveal the critical factors that are required to achieve the demonstrated high supercapacitor performance.
Publisher: American Chemical Society (ACS)
Date: 10-01-2023
Publisher: American Chemical Society (ACS)
Date: 14-09-2023
Publisher: American Chemical Society (ACS)
Date: 16-09-2009
DOI: 10.1021/NN900846P
Abstract: The possibility of effective control of the wetting properties of a nanostructured surface consisting of arrays of amorphous carbon nanoparticles capped on carbon nanotubes using the electrowetting technique is demonstrated. By analyzing the electrowetting curves with an equivalent circuit model of the solid/liquid interface, the long-standing problem of control and monitoring of the transition between the "slippy" Cassie state and the "sticky" Wenzel states is resolved. The unique structural properties of the custom-designed nanocomposites with precisely tailored surface energy without using any commonly utilized low-surface-energy (e.g., polymer) conformal coatings enable easy identification of the occurrence of such transition from the optical contrast on the nanostructured surfaces. This approach to precise control of the wetting mode transitions is generic and has an outstanding potential to enable the stable superhydrophobic capability of nanostructured surfaces for numerous applications, such as low-friction microfluidics and self-cleaning.
Publisher: American Vacuum Society
Date: 2002
DOI: 10.1116/1.1430426
Abstract: Optical emission characteristics of the 500 kHz flat-coil inductively coupled discharges in pure argon, nitrogen, and gas mixtures of Ar+H2, N2+Ar, and N2+H2 are investigated. Variation of input power and operating gas pressure lead to hysteresis in the optical emission intensity (OEI), which is associated with the transitions between the electrostatic (E) and electromagnetic (H) discharge operating regimes. The characteristics of the hysteresis loops and character of mode transitions appear to be different in pure gases and gas mixtures. It has been observed that the E→H transition are always discontinuous, while the H→E transitions appear smooth in pure nitrogen and N2-dominated discharges. Dependence of the E→H transition threshold on gas composition in Ar+N2, Ar+H2, and N2+H2 mixtures is investigated and underlying mechanisms are discussed. It is also shown that the OEI of nitrogen species can efficiently be controlled by small Ar or H2 admixtures. Addition of argon enhances the optical emission of N2, N2+, N, and N+ species, whereas the effect of hydrogen admixture is the opposite.
Publisher: MDPI AG
Date: 28-02-2018
DOI: 10.3390/APP8030353
Publisher: Cambridge University Press (CUP)
Date: 12-1993
DOI: 10.1017/S0022377800017219
Abstract: The dispersion properties and electromagnetic field topography of surface waves propagating along and in the azimuthal direction with respect to a cylindrical metal antenna immersed in a magneto-active plasma are investigated. The external magnetic field is directed along the antenna axis. The presence of a vacuum-gap sheath region separating the antenna from the plasma is assumed. The sheathless case is also considered. The dependence of the surface-wave dispersion properties on magnetic field intensity, plasma density, antenna radius and sheath thickness is presented for structure parameters close to experimental data. The results show qualitative agreement between our theory and experiment. The antenna surface impedance is calculated as well.
Publisher: Elsevier BV
Date: 10-2021
Publisher: IOP Publishing
Date: 05-07-2016
Publisher: Wiley
Date: 19-02-2015
Publisher: Elsevier BV
Date: 06-2021
Publisher: Elsevier BV
Date: 04-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C1NR10860C
Abstract: The possibility for the switch-over of the growth mode from a continuous network to unidirectional arrays of well-separated, self-organized, vertically oriented graphene nanosheets has been demonstrated using a unique, yet simple plasma-based approach. The process enables highly reproducible, catalyst-free synthesis of arrays of graphene nanosheets with reactive open graphitic edges facing upwards. Effective control over the nanosheet length, number density, and the degree of alignment along the electric field direction is achieved by a simple variation of the substrate bias. These results are of interest for environment-friendly fabrication of next-generation nanodevices based on three-dimensional, ordered self-organized nanoarrays of active nanostructures with very large surface areas and aspect ratios, highly reactive edges, and controlled density on the substrate. Our simple and versatile plasma-based approach paves the way for direct integration of such nanoarrays directly into the Si-based nanodevice platform.
Publisher: American Chemical Society (ACS)
Date: 15-09-2020
Abstract: Efficient and selective internalization of nanoscale diamonds (also termed nanodiamonds, NDs) by living cells is of fundamental importance for their bionanotechnological applications. The biocompatibility of NDs is well established and has been suggested to arise from the limited membrane perturbation during their cellular translocation. However, the latter may be affected when cells are subjected to external stress. This study shows that the oxidative stress generated by atmospheric pressure cold plasmas (APCP) alters cell sensitivity to NDs, and their cytotoxicity profile. Both positively and negatively charged NDs are nontoxic to cells, here
Publisher: IOP Publishing
Date: 29-10-2020
Publisher: American Physical Society (APS)
Date: 25-01-2016
Publisher: IOP Publishing
Date: 26-07-2023
Abstract: The Farley-Buneman and Gradient Drift instabilities have been investigated using a fluid model, in a partially ionized dusty electrojet region in which dust and neutral particles constitute a uniform static background. The effects of dissociative electron-ion recombination and dust charge fluctuation on the instabilities also have been taken into account. The electron-ion dynamics are considered to derive the perturbed densities which further lead to the generalized dispersion relation. The dispersion relation describes the propagation of electrojet instabilities having frequency within dust ion acoustic range in a magnetized partially ionized dusty plasma. The dispersion relation is separately solved numerically and analytically for the two values of anisotropy parameters which correspond to the two different altitudes in the electrojet region. It is found that Gradient drift instability is unstable at a much longer wavelength as compared to Farley-Buneman instability both with or without dust. At lower altitudes(90 km) the increase of negative charge on dust decreases the threshold electron drift velocity for Farley-Buneman instability while it shows the opposite behavior at higher altitudes(100 km). A much lower electron drift velocity is required to excite the Gradient drift instability than the Farley-Buneman instability at both altitudes. The dissociative electron-ion recombination d s both modes much more than the dust charge fluctuation. A significant changes in threshold drift velocity is observed for the Farley-Buneman mode as compared to the Gradient Drift mode due to the two main d ing mechanisms. The present analysis is applicable in the lower ionospheric electrojet region where meteoric ablation processes are dominant.
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C4TC01974A
Abstract: Boron-doped carbon nanoflakes were directly synthesized by hot filament chemical vapor deposition, nontoxic boron carbide was used as the boron source.
Publisher: Elsevier BV
Date: 12-2021
Publisher: AIP Publishing
Date: 08-2006
DOI: 10.1063/1.2219378
Abstract: The possibility of deterministic plasma-assisted reshaping of capped cylindrical seed nanotips by manipulating the plasma parameter-dependent sheath width is shown. Multiscale hybrid gas phase/solid surface numerical experiments reveal that under the wide-sheath conditions the nanotips widen at the base and when the sheath is narrow, they sharpen up. By combining the wide- and narrow-sheath stages in a single process, it turns out possible to synthesize wide-base nanotips with long- and narrow-apex spikes, ideal for electron microemitter applications. This plasma-based approach is generic and can be applied to a larger number of multipurpose nanoassemblies.
Publisher: Wiley
Date: 10-04-2017
Publisher: AIP Publishing
Date: 05-2009
DOI: 10.1063/1.3130267
Abstract: An effective control of the ion current distribution over large-area (up to 103 cm2) substrates with the magnetic fields of a complex structure by using two additional magnetic coils installed under the substrate exposed to vacuum arc plasmas is demonstrated. When the magnetic field generated by the additional coils is aligned with the direction of the magnetic field generated by the guiding and focusing coils of the vacuum arc source, a narrow ion density distribution with the maximum current density 117 A m−2 is achieved. When one of the additional coils is set to generate the magnetic field of the opposite direction, an area almost uniform over the substrate of 103 cm2 ion current distribution with the mean value of 45 A m−2 is achieved. Our findings suggest that the system with the vacuum arc source and two additional magnetic coils can be effectively used for the effective, high throughput, and highly controllable plasma processing.
Publisher: Elsevier BV
Date: 02-2022
DOI: 10.1016/J.JHAZMAT.2021.127658
Abstract: The release of toxic fluoride byproducts is a seemingly unavoidable artifact of surface engineering, causing severe environmental and human health problems. Here we propose and implement a new "upcycle hazard against other hazard" concept in the case study of cold atmospheric plasma surface modification of fluoropolymers such as polytetrafluorethylene (PTFE). Capitalizing on the excellent controllability, precision and energy efficiency of the plasma surface processing, complemented with the recently discovered ability of plasmas to activate water to produce a potent electrochemical disinfectant, referred to as the plasma-activated water (PAW), we demonstrate a radically new solution to capture the hazardous gaseous fluorides into the PAW and use the as-fluorinated PAW (F-PAW) as a very effective antimicrobial disinfectant. A customized surface discharge reactor is developed to evaluate the effects of fluorides released from the plasma etching of PTFE on the chemistries in gas-phase plasmas and F-PAW, as well as the antibacterial effect of F-PAW. The results show that gaseous fluorides, including COF
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2002
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2002
Publisher: Springer Science and Business Media LLC
Date: 29-08-2015
Publisher: Wiley
Date: 05-10-2021
Publisher: American Chemical Society (ACS)
Date: 24-04-2023
Publisher: American Vacuum Society
Date: 06-2015
DOI: 10.1116/1.4922237
Abstract: Energy deficiency, global poverty, chronic hunger, chronic diseases, and environment conservation are among the major problems threatening the whole mankind. Nanostructure-based technologies could be a possible solution. Such techniques are now used for the production of many vitally important products including cultured and fermented food, antibiotics, various medicines, and biofuels. On the other hand, the nanostructure-based technologies still demonstrate low efficiency and controllability, and thus still are not capable to decisively address the global problems. Furthermore, future technologies should ensure lowest possible environmental impact by implementing green production principles. One of the most promising approaches to address these challenges are the sophisticatedly engineered biointerfaces. Here, the authors briefly evaluate the potential of the plasma-based techniques for the fabrication of complex biointerfaces. The authors consider mainly the atmospheric and inductively coupled plasma environments and show several ex les of the artificial plasma-created biointerfaces, which can be used for the biotechnological and medical processes, as well as for the drug delivery devices, fluidised bed bioreactors, catalytic reactors, and others. A special attention is paid to the plasma-based treatment and processing of the biointerfaces formed by arrays of carbon nanotubes and graphene flakes.
Publisher: AIP Publishing
Date: 03-2013
DOI: 10.1063/1.4794327
Abstract: The effect of an ordered array of nanocones on a conducting substrate immersed in the plasma on the transport of the plasma ions is investigated. The real conical shape of the cones is rigorously incorporated into the model. The movement of 105 CH3+ ions in the plasma sheath modified by the nanocone array is simulated. The ions are driven by the electric fields produced by the sheath and the nanostructures. The surface charge density and the total charge on the nanotips with different aspect ratios are computed. The ion transport simulation provides important characteristics of the displacement and velocity of the ions. The relative ion distribution along the lateral surfaces of the carbon nanotips is computed as well. It is shown that a rigorous account of the realistic nanostructure shape leads to very different distribution of the ion fluxes on the nanostructured surfaces compared to the previously reported works. The ion flux distribution is a critical factor in the nucleation process on the substrate and determines the nanostructure growth patterns.
Publisher: IOP Publishing
Date: 15-10-2015
Publisher: IOP Publishing
Date: 02-05-2017
Publisher: Springer Science and Business Media LLC
Date: 26-08-2015
DOI: 10.1038/SREP13379
Abstract: Dense arrays of gold-supported silver nanowires of about 100 nm in diameter grown directly in the channels of nanoporous aluminium oxide membrane were fabricated and tested as a novel platform for the immobilization and retention of BSA proteins in the microbial-protective environments. Additional treatment of the silver nanowires using low-temperature plasmas in the inductively-coupled plasma reactor and an atmospheric-pressure plasma jet have demonstrated that the morphology of the nanowire array can be controlled and the amount of the retained protein may be increased due to the plasma effect. A combination of the neutral gold sublayer with the antimicrobial properties of silver nanowires could significantly enhance the efficiency of the platforms used in various biotechnological processes.
Publisher: Springer Science and Business Media LLC
Date: 12-1996
DOI: 10.1007/BF02357451
Publisher: IOP Publishing
Date: 08-2009
Publisher: Elsevier BV
Date: 12-2021
Publisher: Springer Science and Business Media LLC
Date: 19-03-2018
DOI: 10.1038/S41598-018-22911-8
Abstract: Non-equilibrium is one of the important features of an atmospheric gas discharge plasma. It involves complicated physical-chemical processes and plays a key role in various actual plasma processing. In this report, a novel complete non-equilibrium model is developed to reveal the non-equilibrium synergistic effects for the atmospheric-pressure low-temperature plasmas (AP-LTPs). It combines a thermal-chemical non-equilibrium fluid model for the quasi-neutral plasma region and a simplified sheath model for the electrode sheath region. The free-burning argon arc is selected as a model system because both the electrical-thermal-chemical equilibrium and non-equilibrium regions are involved simultaneously in this arc plasma system. The modeling results indicate for the first time that it is the strong and synergistic interactions among the mass, momentum and energy transfer processes that determine the self-consistent non-equilibrium characteristics of the AP-LTPs. An energy transfer process related to the non-uniform spatial distributions of the electron-to-heavy-particle temperature ratio has also been discovered for the first time. It has a significant influence for self-consistently predicting the transition region between the “hot” and “cold” equilibrium regions of an AP-LTP system. The modeling results would provide an instructive guidance for predicting and possibly controlling the non-equilibrium particle-energy transportation process in various AP-LTPs in future.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-2014
Publisher: AIP Publishing
Date: 15-01-2021
DOI: 10.1063/5.0031220
Abstract: Uniform and stable reactivity of atmospheric pressure plasmas is a prerequisite for most applications in fields ranging from materials’ surface processing, environment protection, to energy conversion. Dielectric barrier discharges (DBDs) are among the most promising plasmas to satisfy these requirements. However, the unpredictable and uncontrollable transitions between discharge modes, the limited understanding of the DBD ignition and extinction processes, and the complexity of plasma chemistries and reactions with admixture gases restrict their adoption in industry. Here, we report a practically relevant and elegant solution based on using customized nanosecond (ns) pulse excitation and precise addition of oxygen to an Ar flow. The effects of ns pulses and oxygen on the uniformity and reactivity of the DBD are investigated via quantifying the gap voltage Ug and the discharge current Ig from the current–voltage measurements and quantitative discharge imaging. The electron density, ne, is estimated with Ug and Ig. With increasing Ug, more electron avalanches are ignited and overlap, which facilitate ne, Te, and discharge uniformity, while high Ug induces excessive electrons generated with high ionization rates, resulting in the distortion of the space electric field and reduced stability and uniformity. A small amount of added oxygen favors the production of electrons. Overdosed oxygen molecules capture electrons causing a drop in ne and Te and couple with the effect of the electrical field resulting in the filamentary discharges or complete plasma extinction. The mechanism of the effects of ns pulses and oxygen addition on the uniformity and reactivity of plasmas is based on the electrical measurements and discharge image analysis and is cross-validated by optical emission spectra measurements and the ratio of the Ar intensities’ calculations as indicators of the variation in ne and Te. The results in this work contribute to the realization and controllability of uniform, stable, and reactive plasmas at atmospheric pressure.
Publisher: American Chemical Society (ACS)
Date: 09-11-2022
Abstract: Environmental contamination and energy shortage are among the most critical global issues that require urgent solutions to ensure sustainable ecological balance. Rapid and ultrasensitive monitoring of water quality against pollutant contaminations using a low-cost, easy-to-operate, and environmentally friendly technology is a promising yet not commonly available solution. Here, we demonstrate the effective use of plasma-converted natural bioresources for environmental monitoring. The energy-efficient microplasmas operated at ambient conditions are used to convert erse bioresources, including fructose, chitosan, citric acid, lignin, cellulose, and starch, into heteroatom-doped graphene quantum dots (GQDs) with controlled structures and functionalities for applications as fluorescence-based environmental nanoprobes. The simple structure of citric acid enables the production of monodispersed 3.6 nm averaged-size GQDs with excitation-independent emissions, while the saccharides including fructose, chitosan, lignin, cellulose, and starch allow the synthesis of GQDs with excitation-dependent emissions due to broader size distribution. Moreover, the presence of heteroatoms such as N and/or S in the chemical structures of chitosan and lignin coupled with the highly reactive species generated by the plasma facilitates the one-step synthesis of N, S-codoped GQDs, which offer selective detection of toxic environmental contaminants with a low limit of detection of 7.4 nM. Our work provides an insight into the rapid and green fabrication of GQDs with tunable emissions from natural resources in a scalable and sustainable manner, which is expected to generate impact in the environmental safety, energy conversion and storage, nanocatalysis, and nanomedicine fields.
Publisher: Beilstein Institut
Date: 10-08-2017
DOI: 10.3762/BJNANO.8.166
Abstract: Applications of plasma-produced vertically oriented graphene nanosheets (VGNs) rely on their unique structure and morphology, which can be tuned by the process parameters to understand the growth mechanism. Here, we report on the effect of the key process parameters such as deposition temperature, discharge power and distance from plasma source to substrate on the catalyst-free growth of VGNs in microwave plasmas. A direct evidence for the initiation of vertical growth through nanoscale graphitic islands is obtained from the temperature-dependent growth rates where the activation energy is found to be as low as 0.57 eV. It is shown that the growth rate and the structural quality of the films could be enhanced by (a) increasing the substrate temperature, (b) decreasing the distance between the microwave plasma source and the substrate, and (c) increasing the discharge power. The correlation between the wetting characteristics, morphology and structural quality is established. It is also demonstrated that morphology, crystallinity, wettability and sheet resistance of the VGNs can be varied while maintaining the same sp 3 content in the film. The effects of the substrate temperature and the electric field in vertical alignment of the graphene sheets are reported. These findings help to develop and optimize the process conditions to produce VGNs tailored for applications including sensing, field emission, catalysis and energy storage.
Publisher: IOP Publishing
Date: 05-08-2022
Abstract: As renewable energy is becoming a crucial energy source to meet the global demand, electrochemical energy storage devices become indispensable for efficient energy storage and reliable supply. The electrode material is the key factor determining the energy storage capacity and the power delivery of the devices. Carbon-based materials, specifically graphite, activated carbons etc, are extensively used as electrodes, yet their low energy densities impede the development of advanced energy storage materials. Decoration by nanoparticles of metals, metal oxides, nitrides, carbides, phosphides, chalcogenides and bimetallic components is one of the most promising and easy-to-implement strategies to significantly enhance the structural and electronic properties, pore refinement, charge storage and charge-transfer kinetics of both pristine and doped carbon structures, thereby making their performance promising for next-generation energy storage devices. Structuring the materials at nanoscale is another probable route for better rate performance and charge-transfer kinetics. This review covers the state-of-art nanoparticle decorated nanocarbons (NCs) as materials for battery anode, metal-ion capacitor anode and supercapacitor electrode. A critical analysis of the elemental composition, structure, associated physico-chemical properties and performance relationships of nanoparticle-decorated NC electrodes is provided as well to inform the future development of the next-generation advanced energy storage materials and devices.
Publisher: Public Library of Science (PLoS)
Date: 16-05-2016
Publisher: AIP Publishing
Date: 28-03-2011
DOI: 10.1063/1.3573795
Abstract: A combination of laser plasma ablation and strain control in CdO/ZnO heterostructures is used to produce and stabilize a metastable wurtzite CdO nanophase. According to the Raman selection rules, this nanophase is Raman-active whereas the thermodynamically preferred rocksalt phase is inactive. The wurtzite-specific and thickness/strain-dependent Raman fingerprints and phonon modes are identified and can be used for reliable and inexpensive nanophase detection. The wurtzite nanophase formation is also confirmed by x-ray diffractometry. The demonstrated ability of the metastable phase and phonon mode control in CdO/ZnO heterostructures is promising for the development of next-generation light emitting sources and exciton-based laser diodes.
Publisher: Elsevier BV
Date: 07-2008
Publisher: AIP Publishing
Date: 27-11-2006
DOI: 10.1063/1.2388941
Abstract: The advantages of using low-temperature plasma environments for postprocessing of dense nanotube arrays are shown by means of multiscale hybrid numerical simulations. By controlling plasma-extracted ion fluxes and varying the plasma and sheath parameters, one can selectively coat, dope, or functionalize different areas on nanotube surfaces. Conditions of uniform deposition of ion fluxes over the entire nanotube surfaces are obtained for different array densities. The plasma route enables a uniform processing of lateral nanotube surfaces in very dense (with a step-to-height ratio of 1:4) arrays, impossible via the neutral gas process wherein radical penetration into the internanotube gaps is poor.
Publisher: IOP Publishing
Date: 04-2016
Publisher: Springer Science and Business Media LLC
Date: 09-02-2021
DOI: 10.1038/S41598-021-81346-W
Abstract: Recently, a series of high-purity Ti 3 (Al 1− x Si x )C 2 solid solutions with new compositions ( x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) have been reported with interesting mechanical properties. Here, we have employed density functional theory for Ti 3 (Al 1− x Si x )C 2 solid solutions to calculate a wider range of physical properties including structural, electronic, mechanical, thermal and optical. With the increase of x , a decrease of cell parameters is observed. All elastic constants and moduli increase with x . The Fermi level gradually increases, moving towards and past the upper bound of the pseudogap, when the value of x goes from zero to unity, indicating that the structural stability reduces gradually when the amount of Si increases within the Ti 3 (Al 1− x Si x )C 2 system. In view of Cauchy pressure, Pugh’s ratio and Poisson’s ratio all compositions of Ti 3 (Al 1− x Si x )C 2 are brittle in nature. Comparatively, low Debye temperature, lattice thermal conductivity and minimum thermal conductivity of Ti 3 AlC 2 favor it to be a thermal barrier coating material. High melting temperatures implies that the solid solutions Ti 3 (Al 1− x Si x )C 2 may have potential applications in harsh environments. In the visible region (1.8–3.1 eV), the minimum reflectivity of all compositions for both polarizations is above 45%, which makes them potential coating materials for solar heating reduction.
Publisher: AIP Publishing
Date: 15-07-2009
DOI: 10.1063/1.3177324
Abstract: Here we report on an unconventional Ni–P alloy-catalyzed, high-throughput, highly reproducible chemical vapor deposition of ultralong carbon microcoils using acetylene precursor in the temperature range 700–750 °C. Scanning electron microscopy analysis reveals that the carbon microcoils have a unique double-helix structure and a uniform circular cross-section. It is shown that double-helix carbon microcoils have outstanding superelastic properties. The microcoils can be extended up to 10–20 times of their original coil length, and quickly recover the original state after releasing the force. A mechanical model of the carbon coils with a large spring index is developed to describe their extension and contraction. Given the initial coil parameters, this mechanical model can successfully account for the geometric nonlinearity of the spring constants for carbon micro- and nanocoils, and is found in a good agreement with the experimental data in the whole stretching process.
Publisher: No publisher found
Date: 2020
Publisher: Wiley
Date: 10-2007
Publisher: AIP Publishing
Date: 10-09-2007
DOI: 10.1063/1.2784932
Abstract: A mechanism and model for the vertical growth of platelet-structured vertically aligned single-crystalline carbon nanostructures by the formation of graphene layers on a flat top surface are proposed and verified experimentally. It is demonstrated that plasma-related effects lead to self-sharpening of tapered nanocones to form needlelike nanostructures, in a good agreement with the predicted dependence of the radius of a nanocone’s flat top on the incoming ion flux and surface temperature. The growth mechanism is relevant to a broad class of nanostructures including nanotips, nanoneedles, and nanowires and can be used to improve the predictability of nanofabrication processes.
Publisher: AIP Publishing
Date: 04-2007
DOI: 10.1063/1.2715918
Abstract: Selective and controlled deposition of plasma-grown nanoparticles is one of the pressing problems of plasma-aided nanofabrication. The results of advanced numerical simulations of motion of charge-variable nanoparticles in the plasma presheath and sheath areas and in localized microscopic electric fields created by surface microstructures are reported. Conditions for site-selective deposition of such nanoparticles onto in idual microstructures and open surface areas within a periodic micropattern are formulated. The effects of plasma parameters, surface potential, and micropattern features on nanoparticle deposition are investigated and explained using particle charging and plasma force arguments. The results are generic and applicable to a broad range of nanoparticle-generating plasmas and practical problems ranging from management of nanoparticle contamination in microelectronics to site-selective nanoparticle deposition into specified device locations, and synthesis of advanced microporous materials and nanoparticle superlattices.
Publisher: American Chemical Society (ACS)
Date: 19-04-2012
DOI: 10.1021/AM300300F
Abstract: We report on the application of cold atmospheric-pressure plasmas to modify silica nanoparticles to enhance their compatibility with polymer matrices. Thermally nonequilibrium atmospheric-pressure plasma is generated by a high-voltage radio frequency power source operated in the capacitively coupled mode with helium as the working gas. Compared to the pure polymer and the polymer nanocomposites with untreated SiO(2), the plasma-treated SiO(2)-polymer nanocomposites show higher dielectric breakdown strength and extended endurance under a constant electrical stress. These improvements are attributed to the stronger interactions between the SiO(2) nanoparticles and the surrounding polymer matrix after the plasma treatment. Our method is generic and can be used in the production of high-performance organic-inorganic functional nanocomposites.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2008
Publisher: Elsevier BV
Date: 09-2021
Publisher: Elsevier BV
Date: 03-2021
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 1999
DOI: 10.1109/27.763122
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8GC02800A
Abstract: Here the possibility of plasma-activated water being a green disinfectant, whose bioactivity is closely linked to peroxynitrite generation, was demonstrated.
Publisher: IOP Publishing
Date: 02-06-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2010
DOI: 10.1039/B9NR00371A
Abstract: Nanophase nc-Si/a-SiC films that contain Si quantum dots (QDs) embedded in an amorphous SiC matrix were deposited on single-crystal silicon substrates using inductively coupled plasma-assisted chemical vapor deposition from the reactive silane and methane precursor gases diluted with hydrogen at a substrate temperature of 200 degrees C. The effect of the hydrogen dilution ratio X (X is defined as the flow rate ratio of hydrogen-to-silane plus methane gases), ranging from 0 to 10.0, on the morphological, structural, and compositional properties of the deposited films, is extensively and systematically studied by scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, Raman spectroscopy, Fourier-transform infrared absorption spectroscopy, and X-ray photoelectron spectroscopy. Effective nanophase segregation at a low hydrogen dilution ratio of 4.0 leads to the formation of highly uniform Si QDs embedded in the amorphous SiC matrix. It is also shown that with the increase of X, the crystallinity degree and the crystallite size increase while the carbon content and the growth rate decrease. The obtained experimental results are explained in terms of the effect of hydrogen dilution on the nucleation and growth processes of the Si QDs in the high-density plasmas. These results are highly relevant to the development of next-generation photovoltaic solar cells, light-emitting diodes, thin-film transistors, and other applications.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2011
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0TA01991G
Abstract: Accurate tuning sulfur vacancy of NiCo 2 S 4 nanoparticles enabled by plasma treatment provides a novel and efficient approach to enhance electrochemical performance of supercapattery.
Publisher: Springer Science and Business Media LLC
Date: 14-02-2018
DOI: 10.1038/S41467-018-02871-3
Abstract: The inability of membranes to handle a wide spectrum of pollutants is an important unsolved problem for water treatment. Here we demonstrate water desalination via a membrane distillation process using a graphene membrane where water permeation is enabled by nanochannels of multilayer, mismatched, partially overlapping graphene grains. Graphene films derived from renewable oil exhibit significantly superior retention of water vapour flux and salt rejection rates, and a superior antifouling capability under a mixture of saline water containing contaminants such as oils and surfactants, compared to commercial distillation membranes. Moreover, real-world applicability of our membrane is demonstrated by processing sea water from Sydney Harbour over 72 h with macroscale membrane size of 4 cm 2 , processing ~0.5 L per day. Numerical simulations show that the channels between the mismatched grains serve as an effective water permeation route. Our research will pave the way for large-scale graphene-based antifouling membranes for erse water treatment applications.
Publisher: AIP Publishing
Date: 11-2014
DOI: 10.1063/1.4901813
Abstract: The uniform growth of copper oxide nanowires on the top of copper plate has been investigated during the exposure to radiofrequency plasma discharge in respect to plasma properties and its localization. The copper s les of 10 mm radius and 1 mm in thickness were exposed to argon-oxygen plasma created at discharge power of 150 W. After 10 min, almost uniform growth of nanowires was achieved over large surface. There were significant distortions in nanowire length and shape near the edges. Based on the experimental results, we developed a theoretical model, which took into account a balance in heat released at the flow of the current to the nanowire and rejected from the nanowire. This model established a dependence of the maximal length of the nanowire at dependence on the plasma parameters, where the limiting factor for nanowire growth and distortions in distribution are ballistic effects of ions and their local fluxes. In contrast, the plasma heating by potential interactions of species has very little influence on the length and smaller deviations in flux are allowed for uniformity of growth.
Publisher: Wiley
Date: 1991
Publisher: Wiley
Date: 23-10-2019
Abstract: Conversion of renewable biomass by time- and energy-efficient techniques remains an important challenge. Herein, plasma catalytic liquefaction (PCL) is employed to achieve rapid liquefaction of microalgae under mild conditions. The choice of the catalyst affects both the liquefaction efficiency and the yield of products. The acid catalyst is more effective and gave a liquid yield of 73.95 wt % in 3 min, as opposed to 69.80 wt % obtained with the basic catalyst in 7 min. Analyses of the thus-formed products and the processing environment reveal that the enhanced PCL performance is linked to the rapid increase in temperature under the effect of plasma-induced electric fields and the generation of large quantities of reactive species. Moreover, the obtained solid residue can be simply upgraded to a carbon product suitable for supercapacitor applications. Therefore, the proposed strategy may provide a new avenue for fast and comprehensive utilization of biomass under benign conditions.
Publisher: Springer Science and Business Media LLC
Date: 29-05-2018
DOI: 10.1038/S41598-018-26227-5
Abstract: Production of ethanol by the yeast Saccharomyces cerevisiae is a process of global importance. In these processes, productivities and yields are pushed to their maximum possible values leading to cellular stress. Transient and lasting enhancements in tolerance and performance have been obtained by genetic engineering, forced evolution, and exposure to moderate levels of chemical and/or physical stimuli, yet the drawbacks of these methods include cost, and multi-step, complex and lengthy treatment protocols. Here, plasma agitation is shown to rapidly induce desirable phenotypic changes in S . cerevisiae after a single treatment, resulting in improved conversion of glucose to ethanol. With a complex environment rich in energetic electrons, highly-reactive chemical species, photons, and gas flow effects, plasma treatment simultaneously mimics exposure to multiple environmental stressors. A single treatment of up to 10 minutes performed using an atmospheric pressure plasma jet was sufficient to induce changes in cell membrane structure, and increased hexokinase 2 activity and secondary metabolite production. These results suggest that plasma treatment is a promising strategy that can contribute to improving metabolic activity in industrial microbial strains, and thus the practicality and economics of industrial fermentations.
Publisher: Elsevier BV
Date: 06-2010
Publisher: Elsevier BV
Date: 12-2014
DOI: 10.1016/J.BBAMCR.2014.08.011
Abstract: Atmospheric pressure gas plasma (AGP) generates reactive oxygen species (ROS) that induce apoptosis in cultured cancer cells. The majority of cancer cells develop a ROS-scavenging anti-oxidant system regulated by Nrf2, which confers resistance to ROS-mediated cancer cell death. Generation of ROS is involved in the AGP-induced cancer cell death of several colorectal cancer cells (Caco2, HCT116 and SW480) by activation of ASK1-mediated apoptosis signaling pathway without affecting control cells (human colonic sub-epithelial myofibroblasts CO18, human fetal lung fibroblast MRC5 and fetal human colon FHC). However, the identity of an oxidase participating in AGP-induced cancer cell death is unknown. Here, we report that AGP up-regulates the expression of Nox2 (NADPH oxidase) to produce ROS. RNA interference designed to target Nox2 effectively inhibits the AGP-induced ROS production and cancer cell death. In some cases both colorectal cancer HT29 and control cells showed resistance to AGP treatment. Compared to AGP-sensitive Caco2 cells, HT29 cells show a higher basal level of the anti-oxidant system transcriptional regulator Nrf2 and its target protein sulfiredoxin (Srx) which are involved in cellular redox homeostasis. Silencing of both Nrf2 and Srx sensitized HT29 cells, leads to ROS overproduction and decreased cell viability. This indicates that in HT29 cells, Nrf2/Srx axis is a protective factor against AGP-induced oxidative stress. The inhibition of Nrf2/Srx signaling should be considered as a central target in drug-resistant colorectal cancer treatments.
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/C9NH00586B
Abstract: Two separated Au channels for remarkably anisotropic transport and distribution of electrons and holes in 2D AuSe nanosheets for advanced polarization-sensitive optoelectronics.
Publisher: American Vacuum Society
Date: 09-2013
DOI: 10.1116/1.4821635
Abstract: Plasma-based techniques offer many unique possibilities for the synthesis of various nanostructures both on the surface and in the plasma bulk. In contrast to the conventional chemical vapor deposition and some other techniques, plasma-based processes ensure high level of controllability, good quality of the produced nanomaterials, and reduced environmental risk. In this work, the authors briefly review the unique features of the plasma-enhanced chemical vapor deposition approaches, namely, the techniques based on inductively coupled, microwave, and arc discharges. Specifically, the authors consider the plasmas with the ion/electron density ranging from 1010 to 1014 cm−3, electron energy in the discharge up to ∼10 eV, and the operating pressure ranging from 1 to 104 Pa (up to 105 Pa for the atmospheric-pressure arc discharges). The operating frequencies of the discharges considered range from 460 kHz for the inductively coupled plasmas, and up to 2.45 GHz for the microwave plasmas. The features of the direct-current arc discharges are also examined. The authors also discuss the principles of operation of these systems, as well as the effects of the key plasma parameters on the conditions of nucleation and growth of the carbon nanostructures, mainly carbon nanotubes and graphene. Advantages and disadvantages of these plasma systems are considered. Future trends in the development of these plasma-based systems are also discussed.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2020
Publisher: American Physical Society (APS)
Date: 05-02-2013
Publisher: AIP Publishing
Date: 11-10-2010
DOI: 10.1063/1.3502562
Abstract: The formation of vertically aligned, clearly separated, copper-capped carbon nanocones with a length of up to 500 nm and base diameter of about 150 nm via three-stage process involving magnetron sputtering, N2 plasma treatment, and CH4+N2 plasma growth is studied. The width of gaps between the nanocones can be controlled by the gas composition. The nanocone formation mechanism is explained in terms of strong passivation of carbon in narrow gaps, where the access of plasma ions is hindered and the formation of large CnH2n+2 molecules is possible. This plasma-enabled approach can be used to fabricate nanoelectronic, nanofluidic, and optoelectronic components and devices.
Publisher: Elsevier BV
Date: 10-2021
Publisher: AIP Publishing
Date: 04-2009
DOI: 10.1063/1.3119212
Abstract: The effects of various discharge parameters and ambient gas on the length of He atmospheric plasma jet plumes expanding into the open air are studied. It is found that the voltage and width of the discharge-sustaining pulses exert significantly stronger effects on the plume length than the pulse frequency, gas flow rate, and nozzle diameter. This result is explained through detailed analysis of the I-V characteristics of the primary and secondary discharges which reveals the major role of the integrated total charges of the primary discharge in the plasma dynamics. The length of the jet plume can be significantly increased by guiding the propagating plume into a glass tube attached to the nozzle. This increase is attributed to elimination of the diffusion of surrounding air into the plasma plume, an absence which facilitates the propagation of the ionization front. These results are important for establishing a good level of understanding of the expansion dynamics and for enabling a high degree of control of atmospheric pressure plasmas in biomedical, materials synthesis and processing, environmental and other existing and emerging industrial applications.
Publisher: Springer Science and Business Media LLC
Date: 10-06-2019
Publisher: Elsevier BV
Date: 12-2019
Publisher: AIP Publishing
Date: 02-2013
DOI: 10.1063/1.4791652
Abstract: Cold atmospheric-pressure plasma jets have recently attracted enormous interest owing to numerous applications in plasma biology, health care, medicine, and nanotechnology. A dedicated study of the interaction between the upstream and downstream plasma plumes revealed that the active species (electrons, ions, excited OH, metastable Ar, and nitrogen-related species) generated by the upstream plasma plume enhance the propagation of the downstream plasma plume. At gas flows exceeding 2 l/min, the downstream plasma plume is longer than the upstream plasma plume. Detailed plasma diagnostics and discharge species analysis suggest that this effect is due to the electrons and ions that are generated by the upstream plasma and flow into the downstream plume. This in turn leads to the relatively higher electron density in the downstream plasma. Moreover, high-speed photography reveals a highly unusual behavior of the plasma bullets, which propagate in snake-like motions, very differently from the previous reports. This behavior is related to the hydrodynamic instability of the gas flow, which results in non-uniform distributions of long-lifetime active species in the discharge tube and of surface charges on the inner surface of the tube.
Publisher: IOP Publishing
Date: 03-2019
Publisher: World Scientific Pub Co Pte Lt
Date: 12-2015
DOI: 10.1142/S0217979215502239
Abstract: A theoretical study of TiX 2 (X = Cr, Mn) with C14 Laves phase compounds has been performed by using the first-principles pseudopotential plane-wave method within the generalized gradient approximation (GGA). The electronic properties (Fermi surface and charge density) have been calculated and analyzed. The optical characteristics (dielectric functions, absorption spectrum, conductivity, energy-loss spectrum and reflectivity) are calculated and discussed. The calculated large positive static dielectric constant indicates good dielectric properties. The reflectivity of TiX 2 (X = Cr, Mn) is high in the IR–Visible–UV region up to [Formula: see text][Formula: see text]13 eV showing promise as a good solar heating barrier material. The temperature and pressure dependence of bulk modulus, Debye temperature, specific heats and thermal expansion coefficient are obtained for T = 1200 K and P = 50 GPa through quasi-harmonic Debye model with phononic effects. Fermi surface, optical and thermodynamic properties are very important for practical applications of the materials in optical and other devices.
Publisher: IEEE
Date: 06-2011
Publisher: IOP Publishing
Date: 05-2021
Abstract: The COVID-19, viral influenza, tuberculosis, and other widespread infectious diseases evidence that pathogenic biological aerosols (PBAs) are a serious threat to public health. Different from traditional inactivation methods, such as ultraviolet (UV) light which are only safe to use when people are not present, and high-efficiency particulate filters (HEPA) which merely filter microbes without killing them, atmospheric pressure nonequilibrium plasma (APNP) has shown its tremendous potential in drastically diminishing the aerosol transmission route of the infectious agents through the abatement of PBAs. The key issues to develop high performance APNP based air purification system are critically reviewed. Systematic studies on the hazards of different PBAs and the spread of PBAs in indoor environments guide the development of APNP sources to control communicable diseases. The key six s ling and seven detection methods on PBAs are introduced to analyze the PBA abatement efficiency by APNP. Seven common APNP sources which can remove viruses and bacteria aerosols efficiently developed during the past 8 years are introduced. For the APNP sources with small plasma volume, the electric field and diffusion driven charging are the dominant mechanisms to charge PBAs, while the common methods of dusty plasma research can be adapted to atmospheric-pressure conditions to describe the charging effects of APNP sources with large plasma volume. Plentiful long- and short-lifetime reactive oxygen and nitrogen species (RONS) generated by APNP effectively contribute to inactivation of bacterial aerosols. Current studies suggest that viral aerosols are mainly inactivated by short-lifetime RONS including 1 O 2 , ONOO − and ONOOH. The study on the dissolution and reaction of gaseous RONS in microdroplets and accurate measurements on the evolution of charged PBAs are envisaged to be the focus of future research. Opportunities for multidisciplinary collaborative research to advance the development of next-generation high-performance plasma-based air purifiers are highlighted.
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C1JM13835A
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3CC46218H
Publisher: Elsevier BV
Date: 11-2019
Publisher: Elsevier BV
Date: 2015
Publisher: AIP Publishing
Date: 02-2008
DOI: 10.1063/1.2839035
Abstract: Reliable calculations of the electron/ion energy losses in low-pressure thermally nonequilibrium low-temperature plasmas are indispensable for predictive modeling related to numerous applications of such discharges. The commonly used simplified approaches to calculation of electron/ion energy losses to the chamber walls use a number of simplifying assumptions that often do not account for the details of the prevailing electron energy distribution function (EEDF) and overestimate the contributions of the electron losses to the walls. By direct measurements of the EEDF and careful calculation of contributions of the plasma electrons in low-pressure inductively coupled plasmas, it is shown that the actual losses of kinetic energy of the electrons and ions strongly depend on the EEDF. It is revealed that the overestimates of the total electron/ion energy losses to the walls caused by improper assumptions about the prevailing EEDF and about the ability of the electrons to pass through the repulsive potential of the wall may lead to significant overestimates that are typically in the range between 9 and 32%. These results are particularly important for the development of power-saving strategies for operation of low-temperature, low-pressure gas discharges in erse applications that require reasonably low power densities.
Publisher: American Chemical Society (ACS)
Date: 24-02-2021
Publisher: Elsevier BV
Date: 03-2021
Publisher: Wiley
Date: 19-09-2014
DOI: 10.1002/IJC.28323
Abstract: Cancer is one of the most life-threatening diseases with many forms still regarded as incurable. The conventional cancer treatments have unwanted side effects such as the death of normal cells. A therapy that can accurately target and effectively kill tumor cells could address the inadequacies of the available therapies. Atmospheric gas plasmas (AGP) that are able to specifically kill cancerous cells offer a promising alternative approach compared to conventional therapies. AGP have been shown to exploit tumor-specific genetic defects and a recent trial in mice has confirmed its antitumor effects. The mechanism by which the AGP act on tumor cells but not normal cells is not fully understood. A review of the current literature suggests that reactive oxygen species (ROS) generated by AGP induce death of cancer cells by impairing the function of intracellular regulatory factors. The majority of cancer cells are defective in tumor suppressors that interfere normal cell growth pathways. It appears that pro-oncogene or tumor suppressor-dependent regulation of antioxidant/or ROS signaling pathways may be involved in AGP-induced cancer cell death. The toxic effects of ROS are mitigated by normal cells by adjustment of their metabolic pathways. On the other hand, tumor cells are mostly defective in several regulatory signaling pathways which lead to the loss of metabolic balance within the cells and consequently, the regulation of cell growth. This review article evaluates the impact of AGP on the activation of cellular signaling and its importance for exploring mechanisms for safe and efficient anticancer therapies.
Publisher: Elsevier BV
Date: 11-2014
Publisher: IOP Publishing
Date: 1999
Publisher: AIP Publishing
Date: 17-01-2011
DOI: 10.1063/1.3540645
Publisher: American Chemical Society (ACS)
Date: 08-05-2019
Abstract: Interactions between effects generated by cold atmospheric-pressure plasmas and water have been widely investigated for water purification, chemical and nanomaterial synthesis, and, more recently, medicine and biotechnology. Reactive oxygen and nitrogen species (RONS) play critical roles in transferring the reactivity from gas plasmas to solutions to induce specific biochemical responses in living targets, e.g., pathogen inactivation and biofilm removal. While this approach works well in a single-organism system at a laboratory scale, integration of plasma-enabled biofilm removal into complex real-life systems, e.g., large aquaculture tanks, is far from trivial. This is because it is difficult to deliver sufficient concentrations of the right kind of species to biofilm-covered surfaces while carefully maintaining a suitable physiochemical environment that is healthy for its inhabitants, e.g., fish. In this work, we show that underwater microplasma bubbles (generated by a microplasma-bubble reactor that forms a dielectric barrier discharge at the gas-liquid interface with the applied voltage of 4.0 kV) act as transport vehicles to efficiently deliver reactive plasma species to the target biofilm sites on artificial and living surfaces while keeping healthy water conditions in a multispecies system. The as-generated air microplasma bubbles and plasma-activated water (PAW) both can effectively reduce the existing pathogenic biofilm load by ∼83 and 60%, respectively, after 15 min of discharge at 40 W and prevent any new biofilm from forming. The generation of underwater microplasma bubbles in a custom-made fish tank for less than a minute per day (20 s per time, twice daily) can introduce sufficient quantities of RONS into PAW to reduce the biofilm-infected area by ∼80-90% and improve the health status of Cichlasoma synspilum × Cichlasoma citrinellum blood parrot cichlid fish. Species generated include hydrogen peroxide, ozone, nitrite, nitrate, and nitric oxide. Using mimicked chemical solutions, we show that the plasma-induced nitric oxide acts as a critical bioactive species that triggers the release of cells from the biofilm and their inactivation.
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C5GC02938D
Abstract: A scalable, green method to prepare microporous carbon from sugarcane waste for superior lithium storage capability of Fe 1−x S.
Publisher: AIP Publishing
Date: 21-04-2014
DOI: 10.1063/1.4872254
Abstract: Nucleation and growth of highly crystalline silicon nanoparticles in atmospheric-pressure low-temperature microplasmas at gas temperatures well below the Si crystallization threshold and within a short (100 μs) period of time are demonstrated and explained. The modeling reveals that collision-enhanced ion fluxes can effectively increase the heat flux on the nanoparticle surface and this heating is controlled by the ion density. It is shown that nanoparticles can be heated to temperatures above the crystallization threshold. These combined experimental and theoretical results confirm the effective heating and structure control of Si nanoparticles at atmospheric pressure and low gas temperatures.
Publisher: American Chemical Society (ACS)
Date: 17-08-2023
Publisher: Springer Science and Business Media LLC
Date: 22-12-2016
DOI: 10.1038/SREP39552
Abstract: Atmospheric-pressure plasma and TiO 2 photocatalysis have been widely investigated separately for the management and reduction of microorganisms in aqueous solutions. In this paper, the two methods were combined in order to achieve a more profound understanding of their interactions in disinfection of water contaminated by Escherichia coli . Under water discharges carried out by microplasma jet arrays can result in a rapid inactivation of E. coli cells. The inactivation efficiency is largely dependent on the feed gases used, the plasma treatment time, and the discharge power. Compared to atmospheric-pressure N 2 , He and air microplasma arrays, O 2 microplasma had the highest activity against E. coli cells in aqueous solution, and showed .9% bacterial inactivation efficiency within 4 min. Addition of TiO 2 photocatalytic film to the plasma discharge reactor significantly enhanced the inactivation efficiency of the O 2 microplasma system, decreasing the time required to achieve 99.9% killing of E. coli cells to 1 min. This may be attributed to the enhancement of ROS generation due to high catalytic activity and stability of the TiO 2 photocatalyst in the combined plasma-TiO 2 systems. Present work demonstrated the synergistic effect of the two agents, which can be correlated in order to maximize treatment efficiency.
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3FD00006K
Abstract: Three sustainable plasma-enabled ammonia synthesis routes to zero carbon emissions for chemicals, fertilizers, and biomedical applications coupled with renewable energy.
Publisher: IOP Publishing
Date: 2001
Publisher: IOP Publishing
Date: 27-03-2014
Publisher: IOP Publishing
Date: 13-03-2018
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C3TC32568G
Abstract: Carbon nanoflakes (CNFLs) are synthesized on silicon substrates deposited with carbon islands in a methane environment using hot filament chemical vapor deposition.
Publisher: Informa UK Limited
Date: 08-2014
Publisher: Elsevier BV
Date: 08-2014
Publisher: Elsevier BV
Date: 04-2022
Publisher: IOP Publishing
Date: 6
Publisher: AIP Publishing
Date: 06-2009
DOI: 10.1063/1.3153554
Abstract: Parameters of a discharge sustained in a planar magnetron configuration with crossed electric and magnetic fields are studied experimentally and numerically. By comparing the data obtained in the experiment with the results of calculations made using the proposed theoretical model, conclusion was made about the leading role of the turbulence-driven Bohm electron conductivity in the low-pressure operation mode (up to 1 Pa) of the discharge in crossed electric and magnetic fields. A strong dependence of the width of the cathode sputter trench, associated with the ionization region of the magnetron discharge, on the discharge parameters was observed in the experiments. The experimental data were used as input parameters in the discharge model that describes the motion of secondary electrons across the magnetic field in the ionization region and takes into account the classical, near-wall, and Bohm mechanisms of electron conductivity.
Publisher: Springer Science and Business Media LLC
Date: 06-1991
DOI: 10.1007/BF01039590
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1NA00207D
Abstract: A nanocomposite made of exfoliated vermiculite nanosheets and epoxy is developed for extinguishing fire and protecting wood from fire degradation.
Publisher: Springer Science and Business Media LLC
Date: 09-2013
Publisher: Elsevier BV
Date: 06-2021
Publisher: Springer Science and Business Media LLC
Date: 06-2019
Publisher: Wiley
Date: 31-01-2019
Publisher: Elsevier BV
Date: 09-2011
Publisher: Elsevier BV
Date: 09-2021
Publisher: American Chemical Society (ACS)
Date: 18-09-2023
Publisher: Springer Science and Business Media LLC
Date: 26-02-2020
Publisher: Elsevier BV
Date: 11-2016
Publisher: IOP Publishing
Date: 06-2000
Publisher: MDPI AG
Date: 11-2018
DOI: 10.3390/MI9110565
Abstract: Carbon, one of the most abundant materials, is very attractive for many applications because it exists in a variety of forms based on dimensions, such as zero-dimensional (0D), one-dimensional (1D), two-dimensional (2D), and-three dimensional (3D). Carbon nanowall (CNW) is a vertically-oriented 2D form of a graphene-like structure with open boundaries, sharp edges, nonstacking morphology, large interlayer spacing, and a huge surface area. Plasma-enhanced chemical vapor deposition (PECVD) is widely used for the large-scale synthesis and functionalization of carbon nanowalls (CNWs) with different types of plasma activation. Plasma-enhanced techniques open up possibilities to improve the structure and morphology of CNWs by controlling the plasma discharge parameters. Plasma-assisted surface treatment on CNWs improves their stability against structural degradation and surface chemistry with enhanced electrical and chemical properties. These advantages broaden the applications of CNWs in electrochemical energy storage devices, catalysis, and electronic devices and sensing devices to extremely thin black body coatings. However, the controlled growth of CNWs for specific applications remains a challenge. In these aspects, this review discusses the growth of CNWs using different plasma activation, the influence of various plasma-discharge parameters, and plasma-assisted surface treatment techniques for tailoring the properties of CNWs. The challenges and possibilities of CNW-related research are also discussed.
Publisher: Elsevier BV
Date: 04-2019
Publisher: Elsevier BV
Date: 04-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D2NR06942C
Abstract: To improve operational stability of perovskite (PSK) LEDs, we used red-emitting hydrophobic carbon dots to impart structural stability to 2D PSK and reduce band offset, improving the operational stability of device to 8 hours from less than 2 hours.
Publisher: Wiley
Date: 15-02-2021
Abstract: Ultrashort laser‐gas interaction is a promising candidate for the intense broad band far‐infrared radiation in which the gas ionization and the resultant plasma formation occur consequently. The electron current produced in the process is the most important influential parameter which affects the far‐infrared radiation generation. Although the interacting forces of the process are the space charge electric and the laser electromagnetic forces, the effect of the former one, has not been investigated on the gas‐plasma THz generation. It is noteworthy that the space charge electric force, due to its effect on the electron distribution, has potential influence on the produced electron current and its consequent emission. Here, a 2D relativistic fluid model is presented in which the ions and the resultant space charge field are incorporated. The model investigates the air ionization, electron‐ion plasma formation, and the system's evolution, spatiotemporally. Moreover, as the model is based on the transient electron current, as the source for the electromagnetic pulse radiation, it gives the temporal profile of the radiated field in which the space charge effects are observable. Our results show that the space charge field affects the electron velocity and its resultant current. Therefore, the temporal profiles and litudes of the radiated field components are affected and their resemblance to the experimental data is enhanced. The results indicate that the litude of the radiated field increases in the presence of the space charge field. In addition, it is shown that the space charge effects become more pronounced with the laser intensity.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2008
Publisher: MDPI AG
Date: 09-06-2021
Abstract: Cold atmospheric plasma (CAP) has emerged as a highly selective anticancer agent, most recently in the form of plasma-activated medium (PAM). Since epithelial–mesenchymal transition (EMT) has been implicated in resistance to various cancer therapies, we assessed whether EMT status is associated with PAM response. Mesenchymal breast cancer cell lines, as well as the mesenchymal variant in an isogenic EMT/MET human breast cancer cell system (PMC42-ET/LA), were more sensitive to PAM treatment than their epithelial counterparts, contrary to their responses to other therapies. The same trend was seen in luminal muscle-invasive bladder cancer model (TSU-Pr1/B1/B2) and the non-muscle-invasive basal 5637 bladder cancer cell line. Three-dimensional spheroid cultures of the bladder cancer cell lines were less sensitive to the PAM treatment compared to their two-dimensional counterparts however, incrementally better responses were again seen in more mesenchymally-shifted cell lines. This study provides evidence that PAM preferentially inhibits mesenchymally-shifted carcinoma cells, which have been associated with resistance to other therapies. Thus, PAM may represent a novel treatment that can selectively inhibit triple-negative breast cancers and a subset of aggressive bladder cancers, which tend to be more mesenchymal. Our approach may potentially be utilized for other aggressive cancers exhibiting EMT and opens new opportunities for CAP and PAM as a promising new onco-therapy.
Publisher: Elsevier BV
Date: 06-2018
Publisher: American Physical Society (APS)
Date: 24-06-0006
Publisher: Elsevier BV
Date: 11-2008
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C5NR06537B
Abstract: Graphene, a newly discovered and extensively investigated material, has many unique and extraordinary properties which promise major technological advances in fields ranging from electronics to mechanical engineering and food production. Unfortunately, complex techniques and high production costs hinder commonplace applications. Scaling of existing graphene production techniques to the industrial level without compromising its properties is a current challenge. This article focuses on the perspectives and challenges of scalability, equipment, and technological perspectives of the plasma-based techniques which offer many unique possibilities for the synthesis of graphene and graphene-containing products. The plasma-based processes are amenable for scaling and could also be useful to enhance the controllability of the conventional chemical vapour deposition method and some other techniques, and to ensure a good quality of the produced graphene. We examine the unique features of the plasma-enhanced graphene production approaches, including the techniques based on inductively-coupled and arc discharges, in the context of their potential scaling to mass production following the generic scaling approaches applicable to the existing processes and systems. This work analyses a large amount of the recent literature on graphene production by various techniques and summarizes the results in a tabular form to provide a simple and convenient comparison of several available techniques. Our analysis reveals a significant potential of scalability for plasma-based technologies, based on the scaling-related process characteristics. Among other processes, a greater yield of 1 g × h(-1) m(-2) was reached for the arc discharge technology, whereas the other plasma-based techniques show process yields comparable to the neutral-gas based methods. Selected plasma-based techniques show lower energy consumption than in thermal CVD processes, and the ability to produce graphene flakes of various sizes reaching hundreds of square millimetres, and the thickness varying from a monolayer to 10-20 layers. Additional factors such as electrical voltage and current, not available in thermal CVD processes could potentially lead to better scalability, flexibility and control of the plasma-based processes. Advantages and disadvantages of various systems are also considered.
Publisher: Elsevier BV
Date: 10-2021
Publisher: IOP Publishing
Date: 04-04-2007
Publisher: American Chemical Society (ACS)
Date: 03-06-2022
Publisher: Elsevier BV
Date: 2022
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1GC00198A
Abstract: This work demonstrates the plasma-bubble as an energy efficient and sustainable approach for green and decentralised H 2 O 2 production.
Publisher: AIP Publishing
Date: 15-06-2011
DOI: 10.1063/1.3599893
Abstract: Quantum cascade laser absorption spectroscopy was used to measure the absolute concentration of acetylene in situ during the nanoparticle growth in Ar + C2H2 RF plasmas. It is demonstrated that the nanoparticle growth exhibits a periodical behavior, with the growth cycle period strongly dependent on the initial acetylene concentration in the chamber. Being 300 s at 7.5% of acetylene in the gas mixture, the growth cycle period decreases with the acetylene concentration increasing the growth eventually disappears when the acetylene concentration exceeds 32%. During the nanoparticle growth, the acetylene concentration is small and does not exceed 4.2% at radio frequency (RF) power of 4 W, and 0.5% at RF power of 20 W. An injection of a single acetylene pulse into the discharge also results in the nanoparticle nucleation and growth. The absorption spectroscopy technique was found to be very effective for the time-resolved measurement of the hydrocarbon content in nanoparticle-generating plasmas.
Publisher: American Chemical Society (ACS)
Date: 03-09-2021
Publisher: Wiley
Date: 26-03-2019
Publisher: AIP Publishing
Date: 17-10-2011
DOI: 10.1063/1.3655201
Abstract: Nanosecond dynamics of two separated discharge cycles in an asymmetric dielectric barrier discharge is studied using time-resolved current and voltage measurements synchronized with high-speed (∼5 ns) optical imaging. Nanosecond dc pulses with tailored raise and fall times are used to generate solitary filamentary structures (SFSs) during the first cycle and a uniform glow during the second. The SFSs feature ∼1.5 mm thickness, ∼1.9 A peak current, and a lifetime of several hundred nanoseconds, at least an order of magnitude larger than in common microdischarges. This can be used in alternating localized and uniform high-current plasma treatments in various applications.
Publisher: Wiley
Date: 28-12-2015
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8TC05408H
Abstract: B 2 pairs-substituted MoX 2 monolayers provide options for future 2D electronic devices.
Publisher: Elsevier BV
Date: 05-2018
Publisher: IOP Publishing
Date: 18-11-2020
Abstract: Plasma-activated water (PAW) represents a promising green antibacterial agent for biomedical and agricultural applications. In this study, a novel AC multi-needle-to-water discharge device was developed to investigate the effects of gas flow on the generation and chemical composition of PAW. It is shown that the concentrations of NO 3 − and N(III) ( NO 2 − and HN O 2 ) in the PAW both increased with an extension of the plasma-processing time and a reduction of the gas-flow rate. The absorption of gas-phase products carried by the gas flow from the discharge chamber was found to be beneficial for the generation of both NO 3 − and N(III) in the PAW at a gas flow rate of 20–60 L h −1 , yet their concentrations were still lower than those without any feeding gas. As opposed to NO 3 − or N(III), the H 2 O 2 concentration in the plasma-activated phosphate buffer solution (PAPBS) increased under stronger gas flows and was almost unaffected by absorption in PAPBS. The pH value of PAW increased at higher gas flow rates. A comparison of the N(III) in PAW and PAPBS reflects the effects of the reactions of NO 2 − and H 2 O 2 in the two different working liquids. To quantify the effects of gas flow on the discharge characteristics, gas temperatures were calculated from the optical emission spectra and were proven to be flow-independent near the discharge channel. Fourier transform infrared (FTIR) measurements of the gaseous products during the discharge, and further analysis of possible reaction pathways indicated that by controlling the gas flow in the multi-needle-to-water discharge system, the concentration of long-lived species in PAW could be tuned, which might favor the generation of ONOOH . These findings contribute to a better understanding of effective electric discharge-related mechanisms for enhancing the biochemical and chemical activities of PAW.
Publisher: Springer Science and Business Media LLC
Date: 15-04-2009
Publisher: Elsevier BV
Date: 02-2022
Publisher: Elsevier BV
Date: 2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2CP00547F
Abstract: To gain insights into the mechanisms of plasma chemical product interactions, the dynamic changes of the surface dielectric barrier discharge (SDBD) products are experimentally related to the reduced electric field and gas temperature. The higher applied voltage and frequency cause faster product changes from the O
Publisher: AIP Publishing
Date: 08-2008
DOI: 10.1063/1.2963712
Abstract: Graphitization, a common process involving the transformation of metastable nongraphitic carbon into graphite is one of the major present-day challenges for micro- and nanocarbons due to their unique structural character and highly unusual thermal activation. Here we report on the successful graphitization of nanocrystalline carbon microcoils prepared by catalytic chemical vapor deposition and post-treated in argon atmosphere at temperatures ∼2500 °C for 2 h. The morphology, microstructure, and thermal properties of the carbon microcoils are examined in detail. The graphitization mechanism is discussed by invoking a model of structural transformation of the carbon microcoils. The results reveal that after graphitization the carbon microcoils are prominently purified and feature a clear helical morphology, as well as a more regular and ordered microstructure. The interlayer spacing of the carbon microcoils decreases from 0.36 to 0.34 nm, whereas the mean crystal sizes in the c- and a-directions increase from 1.64 to 2.04 nm and from 3.86 to 7.21 nm, respectively. Thermal treatment also substantially improves the antioxidation properties of the microcoils by lifting the oxidation onset temperature from 550 to 672 °C. This process may be suitable for other nongraphitic micro- and nanomaterials.
Publisher: IOP Publishing
Date: 28-09-2007
Publisher: Elsevier BV
Date: 06-2020
Publisher: AIP Publishing
Date: 15-02-2002
DOI: 10.1063/1.1430893
Abstract: A global electromagnetic model of an inductively coupled plasma sustained by an internal oscillating current sheet in a cylindrical metal vessel is developed. The electromagnetic field structure, profiles of the rf power transferred to the plasma electrons, electron/ion number density, and working points of the discharge are studied, by invoking particle and power balance. It is revealed that the internal rf current with spatially invariable phase significantly improves the radial uniformity of the electromagnetic fields and the power density in the chamber as compared with conventional plasma sources with external flat spiral inductive coils. This configuration offers the possibility of controlling the rf power deposition in the azimuthal direction.
Publisher: Elsevier BV
Date: 05-2002
Publisher: Wiley
Date: 26-10-2012
Abstract: Low-temperature plasmas in direct contact with arbitrary, written linear features on a Si wafer enable catalyst-free integration of carbon nanotubes into a Si-based nanodevice platform and in situ resolution of in idual nucleation events. The graded nanotube arrays show reliable, reproducible, and competitive performance in electron field emission and biosensing nanodevices.
Publisher: Elsevier BV
Date: 10-2019
Publisher: Wiley
Date: 23-09-2021
Abstract: The expected widespread use of wearable and other low‐power healthcare devices has triggered great interest in piezoelectric materials as a promising energy harvester. However, traditional piezoelectric materials suffer from poor interfacial energy transfer when used in self‐charging power cells. Herein, piezoelectric supercapacitors (PSCs) are engineered using MXene‐incorporated polymeric piezo separator and MXene (Ti 3 C 2 T x ) multilayered sheets as electrodes. The MXene‐blended polymer film showed considerable improvement with maximum output voltage of 28 V and current of 1.71 µA. The electromechanical properties studied by piezoelectric force microscopy suggest that the integration of MXene in polyvinylidene fluoride (PVDF) matrix induces the degree of dipole moment alignment, thereby improving the piezoelectric properties of PVDF. At the device level, the PSC featured the capacitance of 61 mF cm –2 , the energy density of 24.9 mJ cm −2 , the maximum power density of 1.3 mW cm −3 , and the excellent long‐term cycling stability. A way is paved toward green, integrated energy harvesting and storing technology for next‐generation self‐powered implantable and wearable electronics.
Publisher: AIP Publishing
Date: 03-10-2011
DOI: 10.1063/1.3645625
Abstract: Effective control of dense, high-quality carbon nanotube arrays using hierarchical multilayer catalyst patterns is demonstrated. Scanning/transmission electron microscopy, atomic force microscopy, Raman spectroscopy, and numerical simulations show that by changing the secondary and tertiary layers one can control the properties of the nanotube arrays. The arrays with the highest surface density of vertically aligned nanotubes are produced using a hierarchical stack of iron nanoparticles and alumina and silica layers differing in thickness by one order of magnitude from one another. The results are explained in terms of the catalyst structure effect on carbon diffusivity.
Publisher: Elsevier BV
Date: 03-2018
Publisher: AIP Publishing
Date: 03-11-2008
DOI: 10.1063/1.3012572
Abstract: The results of the combined experimental and numerical study suggest that nonequilibrium plasma-driven self-organization leads to better size and positional uniformity of nickel nanodot arrays on a Si(100) surface compared with neutral gas-based processes under similar conditions. This phenomenon is explained by introducing the absorption zone patterns, whose areas relative to the small nanodot sizes become larger when the surface is charged. Our results suggest that strongly nonequilibrium and higher-complexity plasma systems can be used to improve ordering and size uniformity in nanodot arrays of various materials, a common and seemingly irresolvable problem in self-organized systems of small nanoparticles.
Publisher: Elsevier BV
Date: 12-2019
Publisher: World Scientific Pub Co Pte Lt
Date: 12-2011
DOI: 10.1142/S1793604711002330
Abstract: Al -doped zinc oxide (AZO) thin films are deposited onto glass substrates using radio-frequency reactive magnetron sputtering and the improvements in their physical properties by post-synthesis thermal treatment are reported. X-ray diffraction spectra show that the structure of films can be controlled by adjusting the annealing temperatures, with the best crystallinity obtained at 400°C under a nitrogen atmosphere. These films exhibit improved quality and better optical transmittance as indicated by the UV-Vis spectra. Furthermore, the sheet resistivity is found to decrease from 1.87 × 10 -3 to 5.63 × 10 -4 Ω⋅cm and the carrier mobility increases from 6.47 to 13.43 cm 2 ⋅ V -1 ⋅ s -1 at the optimal annealing temperature. Our results demonstrate a simple yet effective way in controlling the structural, optical and electrical properties of AZO thin films, which is important for solar cell applications.
Publisher: Elsevier BV
Date: 02-2020
Publisher: Wiley
Date: 04-10-2012
Publisher: Elsevier BV
Date: 08-2008
Publisher: American Chemical Society (ACS)
Date: 31-10-2012
DOI: 10.1021/AM301680A
Abstract: Controlled self-organized growth of vertically aligned carbon nanocone arrays in a radio frequency inductively coupled plasma-based process is studied. The experiments have demonstrated that the gaps between the nanocones, density of the nanocone array, and the shape of the nanocones can be effectively controlled by the process parameters such as gas composition (hydrogen content) and electrical bias applied to the substrate. Optical measurements have demonstrated lower reflectance of the nanocone array as compared with a bare Si wafer, thus evidencing their potential for the use in optical devices. The nanocone formation mechanism is explained in terms of redistribution of surface and volumetric fluxes of plasma-generated species in a developing nanocone array and passivation of carbon in narrow gaps where the access of plasma ions is hindered. Extensive numerical simulations were used to support the proposed growth mechanism.
Publisher: Elsevier BV
Date: 11-2018
DOI: 10.1016/J.TIBTECH.2018.06.010
Abstract: Atmospheric pressure gas plasmas are emerging as a promising treatment in cancer that can supplement the existing set of treatment modalities and, when combined with other therapies, enhance their selectivity and efficacy against resistant cancers. With further optimisation in production and administration of plasma treatment, plasma-enabled therapy has a strong potential to mature as a tool for selectively curing highly resistant solid tumours. Although intense preclinical studies have been conducted to exploit the unique traits of plasma as an oncotherapy, few clinical studies are underway. This review identifies types of cancers and patient groups that most likely benefit from plasma oncotherapy, to introduce clinical practitioners to plasma therapy and accelerate the speed of translating plasma for cancer control in clinics.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-2007
Publisher: Royal Society of Chemistry (RSC)
Date: 2010
DOI: 10.1039/C0NR00366B
Abstract: This feature article introduces a deterministic approach for the rapid, single-step, direct synthesis of metal oxide nanowires. This approach is based on the exposure of thin metal s les to reactive oxygen plasmas and does not require any intervening processing or external substrate heating. The critical roles of the reactive oxygen plasmas, surface processes, and plasma-surface interactions that enable this growth are critically examined by using a deterministic viewpoint. The essentials of the experimental procedures and reactor design are presented and related to the key process requirements. The nucleation and growth kinetics is discussed for typical solid-liquid-solid and vapor-solid-solid mechanisms related to the synthesis of the oxide nanowires of metals with low (Ga, Cd) and high (Fe) melting points, respectively. Numerical simulations are focused on the possibility to predict the nanowire nucleation points through the interaction of the plasma radicals and ions with the nanoscale morphological features on the surface, as well as to control the localized 'hot spots' that in turn determine the nanowire size and shape. This generic approach can be applied to virtually any oxide nanoscale system and further confirms the applicability of the plasma nanoscience approaches for deterministic nanoscale synthesis and processing.
Publisher: AIP Publishing
Date: 11-2011
DOI: 10.1063/1.3657842
Abstract: A simple and effective method of controlling the growth of vertically aligned carbon nanotube arrays in a low-temperature plasma is presented. Ni catalyst was pretreated by plasma immersion ion implantation prior to the nanotube growth by plasma-enhanced chemical vapor deposition. Both the size distribution and the areal density of the catalyst nanoparticles decrease due to the ion-surface interactions. Consequently, the resulting size distribution of the vertically aligned carbon nanotubes is reduced to 50 ∼ 100 nm and the areal density is lowered (by a factor of ten) to 108 cm−2, which is significantly different from the very-high-density carbon nanotube forests commonly produced by thermal chemical vapor deposition. The efficiency of this pretreatment is compared with the existing techniques such as neutral gas annealing and plasma etching. These results are highly relevant to the development of the next-generation nanoelectronic and optoelectronic devices that require effective control of the density of nanotube arrays.
Publisher: AIP Publishing
Date: 20-10-2015
DOI: 10.1063/1.4933366
Abstract: Gas discharge plasmas formed at atmospheric pressure and near room temperature have recently been shown as a promising tool for cancer treatment. The mechanism of the plasma action is attributed to generation of reactive oxygen and nitrogen species, electric fields, charges, and photons. The relative importance of different modes of action of atmospheric-pressure plasmas depends on the process parameters and specific treatment objects. Hence, an in-depth understanding of biological mechanisms that underpin plasma-induced death in cancer cells is required to optimise plasma processing conditions. Here, the intracellular factors involved in the observed anti-cancer activity in melanoma Mel007 cells are studied, focusing on the effect of the plasma treatment dose on the expression of tumour suppressor protein TP73. Over-expression of TP73 causes cell growth arrest and/or apoptosis, and hence can potentially be targeted to enhance killing efficacy and selectivity of the plasma treatment. It is shown that the plasma treatment induces dose-dependent up-regulation of TP73 gene expression, resulting in significantly elevated levels of TP73 RNA and protein in plasma-treated melanoma cells. Silencing of TP73 expression by means of RNA interference inhibited the anticancer effects of the plasma, similar to the effect of caspase inhibitor z-VAD or ROS scavenger N-acetyl cysteine. These results confirm the role of TP73 protein in dose-dependent regulation of anticancer activity of atmospheric-pressure plasmas.
Publisher: IOP Publishing
Date: 04-04-2007
Publisher: Wiley
Date: 08-06-2018
Publisher: Springer Science and Business Media LLC
Date: 07-2020
Publisher: Elsevier BV
Date: 09-2006
Publisher: Elsevier BV
Date: 10-2021
Publisher: Springer Science and Business Media LLC
Date: 03-09-2019
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-2014
Publisher: Elsevier BV
Date: 07-2017
Publisher: AIP Publishing
Date: 10-2014
DOI: 10.1063/1.4897393
Abstract: Complementary experiments and numerical modeling reveal the important role of photo-ionization in the guided streamer propagation in helium-air gas mixtures. It is shown that the minimum electron concentration ∼108 cm−3 is required for the regular, repeated propagation of the plasma bullets, while the streamers propagate in the stochastic mode below this threshold. The stochastic-to-regular mode transition is related to the higher background electron density in front of the propagating streamers. These findings help improving control of guided streamer propagation in applications from health care to nanotechnology and improve understanding of generic pre-breakdown phenomena.
Publisher: Wiley
Date: 03-07-2013
Publisher: IOP Publishing
Date: 11-03-2008
DOI: 10.1088/0957-4484/19/15/155304
Abstract: The results of numerical simulations of nanometer precision distributions of microscopic ion fluxes in ion-assisted etching of nanoscale features on the surfaces of dielectric materials using a self-assembled monolayer of spherical nanoparticles as a mask are presented. It is shown that the ion fluxes to the substrate and nanosphere surfaces can be effectively controlled by the plasma parameters and the external bias applied to the substrate. By proper adjustment of these parameters, the ion flux can be focused onto the areas uncovered by the nanospheres. Under certain conditions, the ion flux distributions feature sophisticated hexagonal patterns, which may lead to very different nanofeature etching profiles. The results presented are generic and suggest viable ways to overcome some of the limitations of the existing plasma-assisted nanolithography.
Publisher: AIP Publishing
Date: 15-03-2011
DOI: 10.1063/1.3553853
Abstract: Characteristics of electrical breakdown of a planar magnetron enhanced with an electromagnet and a hollow-cathode structure, are studied experimentally and numerically. At lower pressures the breakdown voltage shows a dependence on the applied magnetic field, and the voltage necessary to achieve the self-sustained discharge regime can be significantly reduced. At higher pressures, the dependence is less sensitive to the magnetic field magnitude and shows a tendency of increased breakdown voltage at the stronger magnetic fields. A model of the magnetron discharge breakdown is developed with the background gas pressure and the magnetic field used as parameters. The model describes the motion of electrons, which gain energy by passing the electric field across the magnetic field and undergo collisions with neutrals, thus generating new bulk electrons. The electrons are in turn accelerated in the electric field and effectively ionize a sufficient amount of neutrals to enable the discharge self-sustainment regime. The model is based on the assumption about the combined classical and near-wall mechanisms of electron conductivity across the magnetic field, and is consistent with the experimental results. The obtained results represent a significant advance toward energy-efficient multipurpose magnetron discharges.
Publisher: Springer Science and Business Media LLC
Date: 05-11-2014
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0TA02768E
Abstract: Multicomponent NH 3 plasma enhances the carbon removal effect and activates red phosphorus to PH radicals, resulting in simultaneous MOF decomposition and phosphorization at low temperature.
Publisher: AIP Publishing
Date: 14-09-2009
DOI: 10.1063/1.3232210
Abstract: The formation of vertically aligned single-crystalline silicon nanostructures via “self-organized” maskless etching in Ar+H2 plasmas is studied. The shape and aspect ratio can be effectively controlled by the reactive plasma composition. In the optimum parameter space, single-crystalline pyramid-like nanostructures are produced otherwise, nanocones and nanodots are formed. This generic nanostructure formation approach does not involve any external material deposition. It is based on a concurrent sputtering, etching, hydrogen termination, and atom/radical redeposition and can be applied to other nanomaterials.
Publisher: American Chemical Society (ACS)
Date: 09-05-2019
Publisher: American Chemical Society (ACS)
Date: 17-05-2016
Abstract: This Research Article reports on the enhancement of the thermal transport properties of nanocomposite materials containing hexagonal boron nitride in poly(vinyl alcohol) through room-temperature atmospheric pressure direct-current microplasma processing. Results show that the microplasma treatment leads to exfoliation of the hexagonal boron nitride in isopropyl alcohol, reducing the number of stacks from >30 to a few or single layers. The thermal diffusivity of the resulting nanocomposites reaches 8.5 mm(2) s(-1), 50 times greater than blank poly(vinyl alcohol) and twice that of nanocomposites containing nonplasma treated boron nitride nanosheets. From TEM analysis, we observe much less aggregation of the nanosheets after plasma processing along with indications of an amorphous carbon interfacial layer, which may contribute to stable dispersion of boron nitride nanosheets in the resulting plasma treated colloids.
Publisher: Wiley
Date: 13-10-2021
Abstract: Layered molybdenum disulphide (MoS 2 ) crystals in combination with graphene create the opportunity for the development of heterostructures with tailored surface and structural properties for energy storage applications. Herein, 2D heterostructures are developed by growing MoS 2 on epitaxial and self‐standing nanoporous graphene (NPG) using chemical vapor deposition (CVD). The effect of substrate as well as different CVD growth parameters such as temperature, amount of sulfur and MoO 3 precursors, and argon flow on the growth of MoS 2 is systematically investigated. Interestingly, various structures of MoS 2 such as monolayer triangular islands, spirals, standing sheets, and irregular stacked multilayered MoS 2 are successfully developed. The growth mechanism is proposed using different advanced characterization techniques. The formation of a continuous wetting layer with grain boundaries over the surface prior to formation of any other structures is detected. As a proof of principle, MoS 2 /NPG is employed for the first time as anode material in potassium ion battery. The electrode delivers a specific capacity of 389 mAh g −1 with over 98% stability after 200 cycles. The porous structures clearly facilitate the ion transport which is beneficial for the ion battery. These encouraging results open new opportunities to develop hierarchical heterostructures of 2D‐materials for next‐generation energy storage technologies.
Publisher: Elsevier BV
Date: 2012
Publisher: Elsevier BV
Date: 08-2021
Publisher: American Chemical Society (ACS)
Date: 21-05-2021
Publisher: Elsevier BV
Date: 10-2016
Publisher: MDPI AG
Date: 04-07-2017
DOI: 10.3390/NANO7070170
Publisher: Elsevier BV
Date: 12-2020
Publisher: Wiley
Date: 14-05-2020
Publisher: American Chemical Society (ACS)
Date: 19-02-2015
DOI: 10.1021/SC500806S
Publisher: Wiley
Date: 07-03-2014
Publisher: Elsevier BV
Date: 11-2011
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2TA03181G
Abstract: The resulting SnPi@CoP–Ni 5 P 4 /NCF shows an excellent electrocatalytic performance of OER, which is indicated by a low overpotential of 364 mV for transferring j 600 and a low activity decay (2.1%) for the pushed j 100 for 50 h.
Publisher: Frontiers Media SA
Date: 23-02-2022
Abstract: T cells engineered with chimeric antigen receptors (CAR) have demonstrated its widespread efficacy as a targeted immunotherapeutic modality. Yet, concerns on its specificity, efficacy and generalization prevented it from being established into a first-line approach against cancers. By reviewing challenges limiting its clinical application, ongoing efforts trying to resolve them, and opportunities that emerging oncotherapeutic modalities may bring to temper these challenges, we conclude that careful CAR design should be done to avoid the off-tumor effect, enhance the efficacy of solid tumor treatment, improve product comparability, and resolve problems such as differential efficacies of co-stimulatory molecules, cytokine storm, tumor lysis syndrome, myelosuppression and severe hepatotoxicity. As a promising solution, we propose potential synergies between CAR-T therapies and cold atmospheric plasma, an emerging onco-therapeutic strategy relying on reactive species, towards improved therapeutic efficacies and enhanced safety that deserve extensive investigations.
Publisher: Wiley
Date: 25-07-2018
Publisher: Springer Science and Business Media LLC
Date: 27-01-2021
DOI: 10.1038/S41522-020-00180-6
Abstract: Biofilms have several characteristics that ensure their survival in a range of adverse environmental conditions, including high cell numbers, close cell proximity to allow easy genetic exchange (e.g., for resistance genes), cell communication and protection through the production of an exopolysaccharide matrix. Together, these characteristics make it difficult to kill undesirable biofilms, despite the many studies aimed at improving the removal of biofilms. An elimination method that is safe, easy to deliver in physically complex environments and not prone to microbial resistance is highly desired. Cold atmospheric plasma, a lightning-like state generated from air or other gases with a high voltage can be used to make plasma-activated water (PAW) that contains many active species and radicals that have antimicrobial activity. Recent studies have shown the potential for PAW to be used for biofilm elimination without causing the bacteria to develop significant resistance. However, the precise mode of action is still the subject of debate. This review discusses the formation of PAW generated species and their impacts on biofilms. A focus is placed on the diffusion of reactive species into biofilms, the formation of gradients and the resulting interaction with the biofilm matrix and specific biofilm components. Such an understanding will provide significant benefits for tackling the ubiquitous problem of biofilm contamination in food, water and medical areas.
Publisher: Elsevier BV
Date: 10-2021
Publisher: AIP Publishing
Date: 09-12-2005
DOI: 10.1063/1.1826214
Abstract: The results of comprehensive experimental studies of the operation, stability, and plasma parameters of the low-frequency (0.46MHz) inductively coupled plasmas sustained by the internal oscillating rf current are reported. The rf plasma is generated by using a custom-designed configuration of the internal rf coil that comprises two perpendicular sets of eight currents in each direction. Various diagnostic tools, such as magnetic probes, optical emission spectroscopy, and an rf-compensated Langmuir probe were used to investigate the electromagnetic, optical, and global properties of the argon plasma in wide ranges of the applied rf power and gas feedstock pressure. It is found that the uniformity of the electromagnetic field inside the plasma reactor is improved as compared to the conventional sources of inductively coupled plasmas with the external flat coil configuration. A reasonable agreement between the experimental data and computed electromagnetic field topography inside the chamber is reported. The Langmuir probe measurements reveal that the spatial profiles of the electron density, the effective electron temperature, plasma potential, and electron energy distribution robability functions feature a high degree of the radial and axial uniformity and a weak azimuthal dependence, which is consistent with the earlier theoretical predictions. As the input rf power increases, the azimuthal dependence of the global plasma parameters vanishes. The obtained results demonstrate that by introducing the internal oscillated rf currents one can noticeably improve the uniformity of electromagnetic field topography, rf power deposition, and the plasma density in the reactor.
Publisher: Elsevier BV
Date: 09-2020
Publisher: Elsevier BV
Date: 05-2022
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6RA20080J
Abstract: The motion of bioparticles in a microfluidic environment can be actively controlled using several tuneable mechanisms, including hydrodynamic, electrophoresis, dielectrophoresis, magnetophoresis, acoustophoresis, thermophoresis and optical forces.
Publisher: Wiley
Date: 30-04-2018
Publisher: MDPI AG
Date: 29-12-2015
DOI: 10.3390/NANO6010004
Publisher: AIP Publishing
Date: 06-2001
DOI: 10.1063/1.1368397
Abstract: Charging of micron-size particulates, often appearing in fluorocarbon plasma etching experiments, is considered. It is shown that in inductively coupled and microwave slot-excited plasmas of C4F8 and Ar gas mixtures, the equilibrium particle charge and charge relaxation processes are controlled by a combination of microscopic electron, atomic (Ar+ and F+), and molecular ion (CF3+, CF2+, and CF+) currents. The impact of molecular ion currents on the particulate charging and charge relaxation processes is analyzed. It is revealed that in low-power (& .5 kW) microwave slot-excited plasmas, the impact of the combined molecular ion current to the total positive microscopic current on the particle can be as high as 40%. The particulate charge relaxation rate in fluorocarbon plasmas appears to exceed 108 s−1, which is almost one order of magnitude higher than that from purely argon plasmas. This can be attributed to the impact of positive currents of fluorocarbon molecular ions, as well as to the electron density fluctuations with particle charge, associated with electron capture and release by the particulates.
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8TA01325J
Abstract: A bimetallic Ni–Mo nanocomposite as a highly efficient HER catalyst with critical synergetic effect can be obtained from a molybdate incorporated Ni-MOF.
Publisher: Elsevier BV
Date: 04-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/C9MH01353A
Abstract: A dual-redox-additive-enhanced Zn–Br 2 “supercapattery” is demonstrated with battery-level energy density and capacitor-level power density.
Publisher: Wiley
Date: 05-07-2019
Publisher: IOP Publishing
Date: 08-05-2008
Publisher: AIP Publishing
Date: 18-10-2010
DOI: 10.1063/1.3504260
Abstract: The possibility to control the electric resistivity-temperature dependence of the nanosized resistive components made using hierarchical multilevel arrays of self-assembled gold nanoparticles prepared by multiple deposition/annealing is demonstrated. It is experimentally shown that the hierarchical three-level patterns, where the nanoparticles of sizes ranging from several nanometers to several tens of nanometer play a competitive roles in the electric conductivity, demonstrate sharp changes in the activation energy. These patterns can be used for the precise tuning of the resistivity-temperature behavior of nanoelectronic components.
Publisher: AIP Publishing
Date: 15-02-2009
DOI: 10.1063/1.3082023
Abstract: This paper reports on ab initio numerical simulations of the effect of Co and Cu dopings on the electronic structure and optical properties of ZnO, pursued to develop diluted magnetic semiconductors vitally needed for spintronic applications. The simulations are based upon the Perdew-Burke-Enzerh generalized gradient approximation on the density functional theory. It is revealed that the electrons with energies close to the Fermi level effectively transfer only between Cu and Co ions which substitute Zn atoms, and are located in the neighbor sites connected by an O ion. The simulation results are consistent with the experimental observations that addition of Cu helps achieve stable ferromagnetism of Co-doped ZnO. It is shown that simultaneous insertion of Co and Cu atoms leads to smaller energy band gap, redshift of the optical absorption edge, as well as significant changes in the reflectivity, dielectric function, refractive index, and electron energy loss function of ZnO as compared to the doping with either Co or Cu atoms. These highly unusual optical properties are explained in terms of the computed electronic structure and are promising for the development of the next-generation room-temperature ferromagnetic semiconductors for future spintronic devices on the existing semiconductor micromanufacturing platform.
Publisher: Elsevier BV
Date: 05-1994
Publisher: American Chemical Society (ACS)
Date: 05-01-2011
DOI: 10.1021/JP110109X
Publisher: Elsevier BV
Date: 11-2010
Publisher: Informa UK Limited
Date: 20-01-2023
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3NR03468B
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9NR05522C
Abstract: Two-dimensional (2D) transition metal dichalcogenide (TMDC) materials have recently attracted great interest because of their tantalising prospects for a broad range of applications including electronics, optoelectronics, and energy storage. Unlike bulk materials, the device performance of atomically thin 2D materials is determined by the interface, thickness and defects. Plasma processing is very effective for erse modifications of nanoscale 2D TMDC materials, owing to its uniquely controllable, effective processes and energy efficiency. Herein, we critically discuss selected recent advances in plasma modification of 2D TMDC materials and their optical and electronic (including optoelectronic) properties of relevance to applications in hydrogen production, gas sensing and energy storage devices. Challenges and future research opportunities in the relevant research field are presented. This review contributes to directing future advances of plasma processing of TMDC materials for targeted applications.
Publisher: Springer Science and Business Media LLC
Date: 24-04-2021
DOI: 10.1007/S00784-021-03949-X
Abstract: Treatment of implants with peri-implantitis is often unsuccessful due to residual microbial biofilm hindering re-osseointegration. The aim of this study was to treat biofilm-grown titanium (Ti) implants with different modalities involving air abrasion (AA) and cold atmospheric plasma (CAP) to compare the effectiveness in surface decontamination and the alteration reservation of surface topography. Saliva collected from a peri-implantitis patient was used to in vitro develop human biofilm over 35 implants with moderately rough surface. The implants were then mounted onto standardized acrylic blocks simulating peri-implantitis defects and treated with AA (erythritol powder), CAP in a liquid medium, or a combination (COM) of both modalities. The remaining biofilm was measured by crystal violet (CV). Surface features and roughness before and after treatment were assessed by scanning electron microscope (SEM). The data were statistically analyzed using Kruskal-Wallis followed by Tukey’s multiple comparison test. In the present peri-implantitis model, the human complex biofilm growth was successful as indicated by the statistical significance between the negative and positive controls. All the treatment groups resulted in a remarkable implant surface decontamination, with values very close to the negative control for AA and COM. Indeed, statistically significant differences in the comparison between the positive control vs. all the treatment groups were found. SEM analysis showed no post-treatment alterations on the implant surface in all the groups. Decontamination with AA delivering erythritol with or without CAP in liquid medium demonstrated compelling efficacy in the removal of biofilm from implants. All the tested treatments did not cause qualitative alterations to the Ti surface features. No specific effects of the CAP were observed, although further studies are necessary to assess its potential as monotherapy with different settings or in combination with other decontamination procedures. CAP is a promising option in the treatment of peri-implantitis because it has potential to improve the elimination of bacterial plaque from implant surfaces, in inaccessible pockets or during open-flap debridement, and should stimulate the process of the re-osseointegration of affected dental implants by not altering surface features and roughness.
Publisher: Springer Science and Business Media LLC
Date: 03-2017
Publisher: Wiley
Date: 16-07-2021
Abstract: Cuprous halides (CuX) are transparent semiconductors with a range of appealing characteristics, and with targeted applications in electronics, energy storage, and sensing. Here, it is demonstrated that CuX films can be formed at room temperature and atmospheric pressure using a rapid, plasma‐based approach. Crystalline CuX products are formed using dielectric barrier discharge plasma to react liquid small‐molecule precursors (1,2‐dichloro‐4‐X‐benzene, where X = Cl, Br, and I) with a copper substrate via a plasma‐assisted reaction. This process produces a composite film, containing both an organic polymer and the cuprous halide crystallites, with a hierarchical nanostructure. The cuprous halides have the zincblende structure, with sizes ranging from ≈10 to ≈85 nm. By employing either neat or mixed precursors, products including CuCl, CuBr, CuCl 0.1 I 0.9 , and CuBr 0.5 I 0.5 are accessed. Furthermore, the same process can be used to produce AgI films from the iodated precursor molecule on a silver film, demonstrating the remarkable versatility of this approach. This work reveals a flexible new method to produce these technologically relevant I–VII semiconductor films, which can have applications in sensing, batteries, or photovoltaics.
Publisher: AIP Publishing
Date: 09-2011
DOI: 10.1063/1.3633215
Abstract: Nitrogenated carbon nanotips with a low atomic concentration of nitrogen have been synthesized by using a custom-designed plasma-enhanced hot-filament plasma chemical vapor deposition system. The properties (including morphology, structure, composition, photoluminescence, etc.) of the synthesized nitrogenated carbon nanotips are investigated using advanced characterization tools. The room-temperature photoluminescence measurements show that the nitrogenated carbon nanotips can generate two distinct broad emissions located at ∼405 and ∼507 nm, respectively. Through the detailed analysis, it is shown that these two emission bands are attributed to the transition between the lone pair valence and σ* bands, which are related to the sp3 and sp2 C–N bonds, respectively. These results are highly relevant to advanced applications of nitrogenated carbon nanotips in light emitting optoelectronic devices.
Publisher: AIP Publishing
Date: 28-01-2008
DOI: 10.1063/1.2839609
Abstract: It is demonstrated that a magnetic field has a profound effect on the length of a single-wall carbon nanotube (SWCNT) synthesized in the arc discharge. The average length of SWCNT increases by a factor of 2 in discharge with magnetic field as compared with the discharge without magnetic field, and the yield of long nanotubes with lengths above 5μm also increases. A model of SWCNT growth on metal catalyst in arc plasma was developed. Monte-Carlo simulations confirm that the increase of the plasma density in the magnetic field leads to an increase in the nanotube growth rate and thus leads to longer nanotubes.
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4NR01553C
Abstract: Pre-lithiation of a MoS 2 /OLC nano-urchin hybrid structure shows great potential in developing good performance lithium ion batteries with ultra-high initial coulombic efficiency.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2022
Publisher: Elsevier BV
Date: 07-2020
Publisher: AIP Publishing
Date: 12-2009
DOI: 10.1063/1.3274467
Publisher: IEEE
Date: 2002
Publisher: Elsevier BV
Date: 04-2022
Publisher: Elsevier BV
Date: 10-2017
Publisher: American Chemical Society (ACS)
Date: 15-06-2012
DOI: 10.1021/NN302020A
Abstract: Effective control of morphology and electrical connectivity of networks of single-walled carbon nanotubes (SWCNTs) by using rough, nanoporous silica supports of Fe catalyst nanoparticles in catalytic chemical vapor deposition is demonstrated experimentally. The very high quality of the nanotubes is evidenced by the G-to-D Raman peak ratios (>50) within the range of the highest known ratios. Transitions from separated nanotubes on smooth SiO(2) surface to densely interconnected networks on the nanoporous SiO(2) are accompanied by an almost two-order of magnitude increase of the nanotube density. These transitions herald the hardly detectable onset of the nanoscale connectivity and are confirmed by the microanalysis and electrical measurements. The achieved effective nanotube interconnection leads to the dramatic, almost three-orders of magnitude decrease of the SWCNT network resistivity compared to networks of similar density produced by wet chemistry-based assembly of preformed nanotubes. The growth model, supported by multiscale, multiphase modeling of SWCNT nucleation reveals multiple constructive roles of the porous catalyst support in facilitating the catalyst saturation and SWCNT nucleation, consistent with the observed higher density of longer nanotubes. The associated mechanisms are related to the unique surface conditions (roughness, wettability, and reduced catalyst coalescence) on the porous SiO(2) and the increased carbon supply through the supporting porous structure. This approach is promising for the direct integration of SWCNT networks into Si-based nanodevice platforms and multiple applications ranging from nanoelectronics and energy conversion to bio- and environmental sensing.
Publisher: Springer Science and Business Media LLC
Date: 15-01-2018
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9TA07454F
Abstract: The phenethylammonium cation significantly promotes the formation of fully-covered thin-films of hybrid bismuth organohalides with low surface roughness and excellent stability.
Publisher: IOP Publishing
Date: 15-04-2009
Publisher: Elsevier BV
Date: 08-2021
Publisher: Elsevier BV
Date: 03-2006
Publisher: Elsevier BV
Date: 03-2009
Publisher: Elsevier BV
Date: 2002
Publisher: Springer Science and Business Media LLC
Date: 10-2014
DOI: 10.1038/AM.2014.100
Publisher: AIP Publishing
Date: 14-12-2009
DOI: 10.1063/1.3273369
Abstract: Deterministic synthesis of self-organized quantum dot arrays for renewable energy, biomedical, and optoelectronic applications requires control over adatom capture zones, which are presently mapped using unphysical geometric tessellation. In contrast, the proposed kinetic mapping is based on simulated two-dimensional adatom fluxes in the array and includes the effects of nucleation, dissolution, coalescence, and process parameters such as surface temperature and deposition rate. This approach is generic and can be used to control the nanoarray development in various practical applications.
Publisher: Wiley
Date: 09-07-2020
Publisher: Wiley
Date: 20-10-2017
Abstract: A cost-effective hexagonal sphericon hematite with predominant (110) facets for the oxygen evolution reaction (OER) is demonstrated. Sequential incorporation of near-atomic uniformly distributed Ce species and Ni nanoparticles into selected sites of the hematite induces a complex synergistic integration phenomenon that enhances the overall catalytic OER performance. This cheap hexagonal sphericon hematite (Fe ≈ 98%) only needs a small overpotential (η) of 0.34 V to reach 10 mA cm
Publisher: MDPI AG
Date: 18-09-2021
DOI: 10.3390/BIOMEDICINES9091259
Abstract: Cold atmospheric plasma (CAP) is a near-room-temperature, partially ionized gas composed of reactive neutral and charged species. CAP also generates physical factors, including ultraviolet (UV) radiation and thermal and electromagnetic (EM) effects. Studies over the past decade demonstrated that CAP could effectively induce death in a wide range of cell types, from mammalian to bacterial cells. Viruses can also be inactivated by a CAP treatment. The CAP-triggered cell-death types mainly include apoptosis, necrosis, and autophagy-associated cell death. Cell death and virus inactivation triggered by CAP are the foundation of the emerging medical applications of CAP, including cancer therapy, sterilization, and wound healing. Here, we systematically analyze the entire picture of multi-modal biological destruction by CAP treatment and their underlying mechanisms based on the latest discoveries particularly the physical effects on cancer cells.
Publisher: IOP Publishing
Date: 05-2022
Abstract: Selective control of the key parameters of the cold atmospheric plasmas (CAPs) is crucial for erse applications ranging from materials processing, clinical medicine to clean energy generation. In particular, the low gas temperature ( T g ) and high electron number density ( n e ) are both critical for obtaining high treatment efficiency of heat-sensitive materials, yet are challenging to achieve because of the very frequent species collision nature in CAPs. In this paper, selective control of T g and n e in a helium CAP driven by a radio-frequency power supply and operated in an open environment is achieved successfully for the first time numerically and experimentally with the quasi-independent variation windows from −33.7 °C to 49.5 °C (i.e. 239.3 to 322.5 K) for T g and from 2.7 × 10 16 to 6.3 × 10 16 m −3 for n e . This result has expanded the key CAP parameter windows significantly into a previously unachievable domain. The further theoretical analysis of the energy transfer and balance based on the ‘energy tree’ concept and numerical modeling reveals the unique non-equilibrium energy transfer channel allowing selective control of T g and n e . This energy transfer channel is enabled by the two ‘valves’, one for controlling the energy deposition from the external circuit to the discharge cell (valve 1), and another one for controlling the energy exchange between the discharge cell and the environment (valve 2). Our conceptual approach and proof-of-principle demonstration open a new way for the active and selective control of the key CAP parameters, which will be quite important for designing CAP sources with specific requirements and for advancing or even creating new CAP applications in the future.
Publisher: IOP Publishing
Date: 27-07-2020
Publisher: AIP Publishing
Date: 25-09-2017
DOI: 10.1063/1.4996784
Abstract: Perovskite solar cells have emerged as one of the most efficient and low cost technologies for delivering of solar electricity due to their exceptional optical and electrical properties. Commercialization of the perovskite solar cells is, however, limited because of the higher cost and environmentally sensitive organic hole transport materials such as spiro-OMETAD and PEDOT:PSS. In this study, an empirical simulation was performed using the Solar Cell Capacitance Simulator software to explore the MoOx thin film as an alternative hole transport material for perovskite solar cells. In the simulation, properties of MoOx thin films deposited by the electron beam evaporation technique from high purity (99.99%) MoO3 pellets at different substrate temperatures (room temperature, 100 °C and 200 °C) were used as input parameters. The films were highly transparent (& %) and have low surface roughness (≤2 nm) with bandgap energy ranging between 3.75 eV and 3.45 eV. Device simulation has shown that the MoOx deposited at room temperature can work in both the regular and inverted structures of the perovskite solar cell with a promising efficiency of 18.25%. Manufacturing of the full device is planned in order to utilize the MoOx as an alternative hole transport material for improved performance, good stability, and low cost of the perovskite solar cell.
Publisher: Hindawi Limited
Date: 2012
DOI: 10.1155/2012/891318
Abstract: Nanoparticle contrast agents offer the potential to significantly improve existing methods of cancer diagnosis and treatment. Advantages include biocompatibility, selective accumulation in tumor cells, and reduced toxicity. Considerable research is underway into the use of nanoparticles as enhancement agents for radiation therapy and photodynamic therapy, where they may be used to deliver treatment agents, produce localized enhancements in radiation dose and selectively target tumor cells for localized damage. This paper reviews the current status of nanoparticles for cancer treatment and presents preliminary results of a pilot study investigating titanium dioxide nanoparticles for dual-mode enhancement of computed tomography (CT) imaging and kilovoltage radiation therapy. Although titanium dioxide produced noticeable image contrast enhancement in the CT scans, more sensitive detectors are needed to determine whether the nanoparticles can also produce localized dose enhancement for targeted radiation therapy.
Publisher: American Chemical Society (ACS)
Date: 13-07-2020
Publisher: AIP Publishing
Date: 03-2017
DOI: 10.1063/1.4977805
Abstract: The influence of background ionization on the ignition dynamics of the pulsed plasma plume is studied. The ignition delay time of each pulse is investigated by recording the voltage signal and the light emission signal. By changing the frequency, the relationship between the pulse-off time and the ignition delay time is revealed. This indicates that residual active species produced in the previous discharge play a role in the next one. With the decrease in the frequency, both time delay and ignition delay time increase. This is due to the decay of the reactive species densities in the pulse-off time. Lower concentrations of these species lead to a longer ignition delay time. The functions for calculating the ignition delay time are utilized to explain the effect of residual species. The independent data of each discharge also evidence the impact of the previous pulse. The exotic relationship between the ignition delay times of the first two pulses may be due to the electrode configuration used in this work. For a pin-to-plane electrode structure, the active species produced during the breakdown are accumulated around the anode (pin-point) where the discharge initiated for the asymmetrical electric field distribution.
Publisher: Wiley
Date: 12-03-2012
Abstract: Diverse morphologies of multidimensional hierarchical single-crystalline ZnO nanoarchitectures including nanoflowers, nanobelts, and nanowires are obtained by use of a simple thermal evaporation and vapour-phase transport deposition technique by placing Au-coated silicon substrates in different positions inside a furnace at process temperatures as low as 550 °C. The nucleation and growth of ZnO nanostructures are governed by the vapour-solid mechanism, as opposed to the commonly reported vapour-liquid-solid mechanism, when gold is used in the process. The morphological, structural, compositional and optical properties of the synthesized ZnO nanostructures can be effectively tailored by means of the experimental parameters, and these properties are closely related to the local growth temperature and gas-phase supersaturation at the s le position. In particular, room-temperature photoluminescence measurements reveal an intense near-band-edge ultraviolet emission at about 386 nm for nanobelts and nanoflowers, which suggests that these nanostructures are of sufficient quality for applications in, for ex le, optoelectronic devices.
Publisher: IOP Publishing
Date: 05-1995
Publisher: AIP Publishing
Date: 2015
DOI: 10.1063/1.4905522
Abstract: The growth kinetics of single-walled carbon nanotubes (SWCNTs) in a low-temperature, low-pressure reactive plasma is investigated using a multiscale numerical simulation, including the plasma sheath and surface diffusion modules. The plasma-related effects on the characteristics of SWCNT growth are studied. It is found that in the presence of reactive radicals in addition to energetic ions inside the plasma sheath area, the effective carbon flux, and the growth rate of SWCNT increase. It is shown that the concentration of atomic hydrogen and hydrocarbon radicals in the plasma plays an important role in the SWCNT growth. The effect of the effective carbon flux on the SWCNT growth rate is quantified. The dependence of the growth parameters on the substrate temperature is also investigated. The effects of the plasma sheath parameters on the growth parameters are different in low- and high-substrate temperature regimes. The optimum substrate temperature and applied DC bias are estimated to maximize the growth rate of the single-walled carbon nanotubes.
Publisher: Wiley
Date: 05-04-2016
Abstract: Manganese oxides are promising pseudocapacitve materials for achieving both high power and energy densities in pseudocapacitors. However, it remains a great challenge to develop MnO2 -based high-performance electrodes due to their low electrical conductance and poor stability. Here we show that MnO2 nanowires anchored on electrochemically modified graphite foil (EMGF) have a high areal capacitance of 167 mF cm(-2) at a discharge current density of 0.2 mA cm(-2) and a high capacitance retention after 5000 charge/discharge cycles (115 %), which are among the best values reported for any MnO2 -based hybrid structures. The EMGF support can also be recycled and the newly deposited MnO2 -based hybrids retain similarly high performance. These results demonstrate the successful preparation of pseudocapacitors with high capacity and cycling stability, which may open a new opportunity towards a sustainable and environmentally friendly method of utilizing electrochemical energy storage devices.
Publisher: IOP Publishing
Date: 13-12-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6NR03702J
Abstract: Highly size-controllable synthesis of free-standing perfectly crystalline silicon carbide nanocrystals has been achieved for the first time through a plasma-based bottom-up process. This low-cost, scalable, ligand-free atmospheric pressure technique allows fabrication of ultra-small (down to 1.5 nm) nanocrystals with very low level of surface contamination, leading to fundamental insights into optical properties of the nanocrystals. This is also confirmed by their exceptional photoluminescence emission yield enhanced by more than 5 times by reducing the nanocrystals sizes in the range of 1-5 nm, which is attributed to quantum confinement in ultra-small nanocrystals. This method is potentially scalable and readily extendable to a wide range of other classes of materials. Moreover, this ligand-free process can produce colloidal nanocrystals by direct deposition into liquid, onto biological materials or onto the substrate of choice to form nanocrystal films. Our simple but efficient approach based on non-equilibrium plasma environment is a response to the need of most efficient bottom-up processes in nanosynthesis and nanotechnology.
Publisher: IOP Publishing
Date: 25-03-2020
Publisher: Cold Spring Harbor Laboratory
Date: 16-02-2020
DOI: 10.1101/2020.02.15.947085
Abstract: Oncogenes are genes whose malfunctions play critical roles in cancer development, and their discovery is a major aim of cancer mechanisms study. By counting the mutation frequency, oncogenes have been identified with frequent mutations, while it is believed that many more oncogenes could be discovered by differential mutational profile analysis. However, it is common that current methods only utilize mutations in the cancer population, which have an obvious bias in background mutation modelling. To predict oncogenes efficiently, we developed a method, DGAT-onco that analyzed the frequency distribution and functional impacts of mutations in both cancer and natural population. Our method can capture the mutational difference of two population, and provide a comprehensive view of genomics basis underlying cancer development. DGAT-onco was constructed by germline mutations from the 1000 Genomes project and somatic mutations of 33 cancer types from the Cancer Genome Atlas (TCGA) dataset. Its reliability was verified on an independent test set including 19 cancers from other sources. We demonstrated that our method is more effective than alternative methods in oncogenes discovering. Using this approach achieves higher classification performance in oncogene discovery than 6 alternative methods, and 22.8% significant genes identified by our method were verified as oncogenes by the Cancer Gene Census (CGC). DGAT-onco is available at hanghaoyang0/DGAT-onco . yangyd25@mail.sysu.edu.cn or zhaohy8@mail.sysu.edu.cn
Publisher: IOP Publishing
Date: 18-11-2008
DOI: 10.1088/0957-4484/19/49/495302
Abstract: Porous high surface area thin films of nanosheet-shaped monoclinic MoO(3) were deposited onto platinized Si substrates using patch antenna-based atmospheric microplasma processing. The films were characterized by high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM) and electrochemical analysis. The electrochemical analysis shows original redox peaks and high charge capacity, and also indicates a reversible electrochemical behaviour particularly beneficial for applications in Li-ion batteries. SEM shows that the films are highly porous and consist of nanosheets 50-100 nm thick with surface dimensions in the micrometre range. HRTEM reveals that the MoO(3) nanosheets consist of the monoclinic beta phase of MoO(3). These intricate nanoarchitectures made of monoclinic MoO(3) nanosheets have not been studied previously in the context of applications in Li-ion batteries and show superior structural and morphological features that enable effective insertion of Li ions.
Publisher: Springer Science and Business Media LLC
Date: 03-04-2013
DOI: 10.1038/SREP01599
Publisher: Elsevier BV
Date: 11-2013
Publisher: Elsevier BV
Date: 09-2008
Publisher: Elsevier BV
Date: 09-2020
Publisher: Springer Science and Business Media LLC
Date: 04-1991
DOI: 10.1007/BF01080776
Publisher: MDPI AG
Date: 31-07-2017
DOI: 10.3390/MA10080884
Publisher: Elsevier BV
Date: 03-2017
DOI: 10.1016/J.BIOS.2016.04.072
Abstract: Here, we present a rapid, low-temperature (200°C) plasma-enabled synthesis of graphene micro-islands (GMs). Morphological analyses of GMs by scanning electron microscopy (SEM) and atomic force microscopy (AFM) feature a uniform and open-networked array of aggregated graphene sheets. Structural and surface chemical characterizations by Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) support the presence of thin graphitic edges and reactive oxygen functional groups. We demonstrate that these inherent properties of GMs enable its multifunctional capabilities as a bioactive interface. GMs exhibit a biocompatibility of 80% cell viability with primary fibroblast lung cells after 5 days. Further, GMs were assembled into an impedimetric genosensor, and its performance was characterized by electrochemical impedance spectroscopy (EIS). A dynamic sensing range of 1pM to 1nM is reported, and a limit of quantification (LOQ) of 2.03×10
Publisher: Wiley
Date: 26-06-2019
Abstract: This paper presents the development and experimental analysis of a curved microelectrode platform for the DEP deformation of breast cancer cells (MDA-MB-231). The platform is composed of arrays of curved DEP microelectrodes which are patterned onto a glass slide and s les containing MDA-MB-231 cells are pipetted onto the platform's surface. Finite element method is utilised to characterise the electric field gradient and DEP field. The performance of the system is assessed with MDA-MB-231 cells in a low conductivity 1% DMEM suspending medium. We applied sinusoidal wave AC potential at peak to peak voltages of 2, 5, and 10 V
Publisher: Public Library of Science (PLoS)
Date: 26-06-2015
Publisher: Elsevier BV
Date: 12-2021
Publisher: Springer Science and Business Media LLC
Date: 05-1991
DOI: 10.1007/BF01036851
Publisher: IOP Publishing
Date: 09-2021
Abstract: Low-power, flexible, and properly encapsulated integrated circuits are the basic requirements of the solution-processed printed and wearable electronic prototypes for various emerging applications including display circuits, sensors, and radio-frequency identification tags. The organic field-effect transistor is one of the important types of devices used in such prototypes and its industrial applicability is essential for the printed electronics technology. The performance deterioration upon encapsulated through the thick layer of air-stable dielectric material such as amorphous fluoropolymer [CYTOP] - must be compensated by device engineering. In this work, we used furan and thiophene flanked diketopyrrolopyrrole donor-acceptor conjugated polymers namely PDPPF-DTT and PDPPT-DTT, and its comparative study was performed using Cytop as a dielectric material. The work advances interface engineering towards the single-gate and dual-gate organic transistors. Dual-gate transistors performance modulation using Cytop dielectric opens new research avenues towards stability enhancement of such transistors for real-world applications.
Publisher: No publisher found
Date: 2022
DOI: 10.1039/D2GC01303G
Publisher: American Chemical Society (ACS)
Date: 19-01-2021
Publisher: Wiley
Date: 18-03-2021
Publisher: Springer Science and Business Media LLC
Date: 05-1993
DOI: 10.1007/BF01091426
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1NR02966E
Abstract: The bifunctional electrocatalyst C–N-MoS 2 /CC-700 with Mo–N links and unsaturated S defects is designed by bi-elemental C and N doping in the CVD process.
Publisher: American Chemical Society (ACS)
Date: 02-11-2021
Publisher: Springer Science and Business Media LLC
Date: 14-10-2016
DOI: 10.1038/SREP35353
Abstract: Schistosoma japonicum is a widespread human and animal parasite that causes intestinal and hepatosplenic schistosomiasis linked to colon, liver and bladder cancers, and anemia. Estimated 230 million people are currently infected with Schistosoma spp, with 779 million people at risk of contracting the parasite. Infection occurs when a host comes into contact with cercariae, a planktonic larval stage of the parasite, and can be prevented by inactivating the larvae, commonly by chemical treatment. We investigated the use of physical non-equilibrium plasma generated at atmospheric pressure using custom-made dielectric barrier discharge reactor to kill S. japonicum cercariae. Survival rate decreased with treatment time and applied power. Plasmas generated in O 2 and air gas discharges were more effective in killing S. japonicum cercariae than that generated in He, which is directly related to the mechanism by which cercariae are inactivated. Reactive oxygen species, such as O atoms, abundant in O 2 plasma and NO in air plasma play a major role in killing of S. japonicum cercariae via oxidation mechanisms. Similar level of efficacy is also shown for a gliding arc discharge plasma jet generated in ambient air, a system that may be more appropriate for scale-up and integration into existing water treatment processes.
Publisher: American Chemical Society (ACS)
Date: 20-02-2019
Publisher: Elsevier BV
Date: 08-2018
Publisher: American Chemical Society (ACS)
Date: 18-08-2017
Abstract: Herein, MoO
Publisher: AIP Publishing
Date: 07-06-2010
DOI: 10.1063/1.3449118
Abstract: The electronic transport in both intrinsic and acid-treated single-walled carbon nanotube networks containing more than 90% semiconducting nanotubes is investigated using temperature-dependent resistance measurements. The semiconducting behavior observed in the intrinsic network is attributed to the three-dimensional electron hopping mechanism. In contrast, the chemical doping mechanism in the acid-treated network is found to be responsible for the revealed metal-like linear resistivity dependence in a broad temperature range. This effective method to control the electrical conductivity of single-walled carbon nanotube networks is promising for future nanoscale electronics, thermometry, and bolometry.
Publisher: IOP Publishing
Date: 02-2023
Abstract: Two modes of the atmospheric-pressure plasma discharge, distinguished by the dominant O 3 and NO x species are studied numerically and experimentally. To investigate the mode transition mechanisms, here we develop a global chemical kinetics model for the atmospheric-pressure dielectric barrier discharge involving 63 species and 750 reactions. Validated by the experimental results, the model accurately describes the mode transition. The N, O, O 2 (a), and O 2 (b) are the essential transient intermediate species for the O 3 and NO x production and loss reactions. The in idual and synergistic effects of the specific discharge energy and the gas temperature on the species density and the relative contributions of the dominant reactions are quantified under the increasing discharge voltage conditions. The modeling results indicate that the gas temperature and specific discharge energy both contributed to the discharge mode transition, while the decisive factors affecting the change of the O 3 and NO x density are different in the respective modes. These insights contribute to erse plasma applications in biomedicine, agriculture, food, and other fields where selective and controlled production of O 3 and NO x species is the key for the desired plasma performance.
Publisher: American Chemical Society (ACS)
Date: 13-11-2019
Publisher: Elsevier BV
Date: 06-2014
DOI: 10.1016/J.IJANTIMICAG.2014.01.025
Abstract: Cold atmospheric pressure plasma (APP) is a recent, cutting-edge antimicrobial treatment. It has the potential to be used as an alternative to traditional treatments such as antibiotics and as a promoter of wound healing, making it a promising tool in a range of biomedical applications with particular importance for combating infections. A number of studies show very promising results for APP-mediated killing of bacteria, including removal of biofilms of pathogenic bacteria such as Pseudomonas aeruginosa. However, the mode of action of APP and the resulting bacterial response are not fully understood. Use of a variety of different plasma-generating devices, different types of plasma gases and different treatment modes makes it challenging to show reproducibility and transferability of results. This review considers some important studies in which APP was used as an antibacterial agent, and specifically those that elucidate its mode of action, with the aim of identifying common bacterial responses to APP exposure. The review has a particular emphasis on mechanisms of interactions of bacterial biofilms with APP.
Publisher: Elsevier BV
Date: 07-2020
Publisher: AIP Publishing
Date: 30-01-2012
DOI: 10.1063/1.3681782
Abstract: The formation of clearly separated vertical graphene nanosheets on silicon nanograss support is demonstrated. The plasma-enabled, two-stage mask-free process produced self-organized vertical graphenes of a few carbon layers (as confirmed by advanced microanalysis), prominently oriented in the substrate center–substrate edge direction. It is shown that the width of the alignment zone depends on the substrate conductivity, and thus the electric field in the vicinity of the growth surface is responsible for the graphene alignment. This finding is confirmed by the Monte Carlo simulations of the ion flux distribution in the silicon nanograss pattern.
Publisher: IOP Publishing
Date: 06-07-2009
Publisher: Elsevier BV
Date: 09-2020
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-2001
DOI: 10.1109/27.923688
Publisher: Wiley
Date: 25-08-2017
Abstract: For the first time, we have reported in this study an ab initio investigation on elastic properties, Debye temperature, Mulliken population, Vickers hardness, and charge density of the two recently synthesized superconducting ScRhP and ScIrP pnictides. The optimized cell parameters show fair agreement with the experimental results. The mechanical stability of both ternary phosphides is confirmed via the calculated elastic constants. Both compounds are ductile in nature and damage tolerant. ScIrP is expected to be elastically more anisotropic than ScRhP. The estimated value of Debye temperature predicts that ScRhP is thermally more conductive than ScIrP and the phonon frequency in ScRhP is higher than that in ScIrP. Both pnictides are soft and easily machinable due to their low Vickers hardness. Moreover, the hardness of ScRhP is lower due to the presence of antibonding Rh–Rh in ScRhP. The metallic conductivity of ScRhP reduces significantly when Rh is replaced with Ir. The main contribution to the total density of states (TDOS) at Fermi‐level ( E F ) comes from d‐electrons of Sc and Rh/Ir in both pnictides. These two ternary compounds are characterized mainly by metallic and covalent bonding with little ionic contribution. The calculated superconducting transition temperatures fairly coincide with the reported measured values.
Publisher: Begell House
Date: 2016
Publisher: Wiley
Date: 09-07-2021
Abstract: In the present study, A2780 CP and SKOV‐3 cells, relevant to ovarian cancer and granulosa cells, as normal ovarian cells, were evaluated through cold atmospheric plasma (CAP) directly, indirectly, and by a concomitant modality of plasma‐activated medium (PAM) with common drugs to overcome chemotherapy resistance in ovarian cancer. Our results confirm the high potential of PAM in comparison to common drugs and CAP for the selected cell lines, and the selectivity mechanism was related to the pH and concentration of H 2 O 2 , NO 2 − , and NO 3 − reactive species in the plasma‐treated medium. Our data confirm that PAM alone and in combination with carboplatin sensitizes cancer cells to carboplatin, inhibits the SOD1 gene, and selectively induces apoptosis accompanied by high expression of p53, bax, and activation of caspase‐3.
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0RE00069H
Abstract: Green plasma-based technology production of N-doped NPs for a new agri-tech revolution in pest control.
Publisher: Royal Society of Chemistry (RSC)
Date: 2010
DOI: 10.1039/C0NR00416B
Abstract: The unique properties of graphene and carbon nanotubes made them the most promising nanomaterials attracting enormous attention, due to the prospects for applications in various nanodevices, from nanoelectronics to sensors and energy conversion devices. Here we report on a novel deterministic, single-step approach to simultaneous production and magnetic separation of graphene flakes and carbon nanotubes in an arc discharge by splitting the high-temperature growth and low-temperature separation zones using a non-uniform magnetic field and tailor-designed catalyst alloy, and depositing nanotubes and graphene in different areas. Our results are very relevant to the development of commercially-viable, single-step production of bulk amounts of high-quality graphene.
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D0EE03407J
Abstract: Polyoxometalates as anionic molecular metal oxides clusters with open frameworks and rich redox chemistry have outstanding versatility in energy conversion and storage research.
Publisher: Wiley
Date: 23-12-2021
Publisher: Elsevier BV
Date: 06-1993
Publisher: Elsevier BV
Date: 12-2017
Publisher: Elsevier BV
Date: 12-2013
Publisher: AIP Publishing
Date: 15-10-2012
DOI: 10.1063/1.4759047
Abstract: The electron field emission (EFE) properties of nitrogenated carbon nanotips (NCNTPs) were studied under high-vacuum conditions. The NCNTPs were prepared in a plasma-assisted hot filament chemical vapor deposition system using CH4 and N2 as the carbon and nitrogen sources, respectively. The work functions of NCNTPs were measured using x-ray photoelectron spectroscopy. The morphological and structural properties of NCNTPs were studied by field emission scanning electron microscopy, micro-Raman spectroscopy, and x-ray photoelectron spectroscopy. The field enhancement factors of NCNTPs were calculated using relevant EFE models based on the Fowler-Nordheim approximation. Analytical characterization and modeling results were used to establish the relations between the EFE properties of NCNTPs and their morphology, structure, and composition. It is shown that the EFE properties of NCNTPs can be enhanced by the reduction of oxygen termination on the surface as well as by increasing the ratio of the NCNTP height to the radius of curvature at its top. These results also suggest that a significant amount of electrons is emitted from other surface areas besides the NCNTP tops, contrary to the common belief. The outcomes of this study advance our knowledge on the electron emission properties of carbon nanomaterials and contribute to the development of the next-generation of advanced applications in the fields of micro- and opto-electronics.
Publisher: Springer Science and Business Media LLC
Date: 25-11-2021
DOI: 10.1038/S41467-021-27071-4
Abstract: Due to complex structure and surface functionalities, photoluminescence mechanisms of Carbon Dots are unknown, and it is challenging to synthesize Carbon Dots to achieve the desired optical properties. Herein, Carbon Dots simultaneously exhibiting high-color-purity (FWHM~24 nm) long wavelength one-photon fluorescence emission at 620 nm and NIR induced two-photon fluorescence emission at 630 and 680 nm are prepared by edge amino protonation treatment. Systematic analysis reveals that the protonation of 2,3-diaminophenazine changes the molecular state of Carbon Dots, decreases the photon transition band gap, and triggers red fluorescence emission with the dramatically narrowed peak width. As the oxidation products of reactant o-phenylendiamine, the emergence of 2,3-diaminophenazine as a photoluminescence determiner suggests that fluorophore products of precursor conversion are viable determinants of the desired luminescence properties of Carbon Dots. This work shows a new way for predicting and controlling photoluminescence properties of Carbon Dots, and may guide the development of tunable Carbon Dots for a broad range of applications.
Publisher: IOP Publishing
Date: 20-05-2020
Publisher: Society of Fiber Science and Technology Japan
Date: 2022
Publisher: Springer Science and Business Media LLC
Date: 06-11-2018
DOI: 10.1007/S10544-018-0341-1
Abstract: Cell contact formation, which is the process by which cells are brought into close proximity is an important biotechnological process in cell and molecular biology. Such manipulation is achieved by various means, among which dielectrophoresis (DEP) is widely used due to its simplicity. Here, we show the advantages in the judicious choice of the DEP microelectrode configuration in terms of limiting undesirable effects of dielectric heating on the cells, which could lead to their inactivation or death, as well as the possibility for cell clustering, which is particularly advantageous over the linear cell chain arrangement typically achieved to date with DEP. This study comprises of experimental work as well as mathematical modeling using COMSOL. In particular, we establish the parameters in a capillary-based microfluidic system giving rise to these optimum cell-cell contact configurations, together with the possibility for facilitating other cell manipulations such as spinning and rotation, thus providing useful protocols for application into microfluidic bioparticle manipulation systems for diagnostics, therapeutics or for furthering research in cellular bioelectricity and intercellular interactions.
Publisher: Elsevier BV
Date: 07-2022
DOI: 10.1016/J.JAND.2022.01.012
Abstract: Practice guidelines for coronary heart disease and type 2 diabetes recommend promoting the Mediterranean dietary pattern (MDP), which improves cardiometabolic risk markers and may prevent disease progression and complications. It is unknown to what extent the MDP is recommended in routine care for patients with these conditions, particularly in multiethnic settings. The study aim was to explore multidisciplinary health care professionals' perspectives on recommending the MDP in routine care for patients with coronary heart disease or type 2 diabetes and barriers and enablers to its implementation. A qualitative description design was employed, utilizing semistructured in idual interviews to collect data. Fifty-seven clinicians (21 nurses, 19 doctors, 13 dietitians, and 4 physiotherapists) routinely managing relevant patients across hospital and community settings in a metropolitan health service in Australia participated in interviews between November 2019 and March 2020. Interviews were audiorecorded, transcribed verbatim, and analyzed using thematic analysis. Four overarching themes were identified highlighting that the MDP was not routinely recommended: current dietary practices (all clinicians perceived they had a role in dietary care but prioritization varied. There was a legacy of single nutrient-based strategies and disease silos) clinician-centered barriers to recommending MDP (limited MDP knowledge and practice skills and variable understanding and acceptance of evidence supporting its use. This was related to lack of education and training about the diet and personal interest/experience) organizational culture and resources influence dietary care (MDP not embedded in service culture or current clinic tools and resources, with limited dietary knowledge exchange within and across multidisciplinary teams) and perceived patient-centered barriers to implementation of MDP (socioeconomic challenges in a multicultural setting, and a lack of belief in patient capabilities to improve diet adherence). Clinician and organizational factors, compounded by perceptions about patient acceptance, influence recommendations of the MDP for patients with coronary heart disease or type 2 diabetes. These factors should be addressed to improve translation of MDP evidence into practice.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9TA00070D
Abstract: Development of highly efficient and low-cost electrocatalysts for the oxygen evolution reaction (OER) with high electrical conductivity and chemical stability is critical for various energy conversion devices and systems, yet still remains a formidable challenge.
Publisher: SPIE
Date: 24-09-2013
DOI: 10.1117/12.2022820
Publisher: Wiley
Date: 15-05-2018
Publisher: IOP Publishing
Date: 11-10-2023
Publisher: Wiley
Date: 22-05-2201
Publisher: American Chemical Society (ACS)
Date: 06-01-2020
Publisher: IOP Publishing
Date: 25-09-2017
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2022
Publisher: IOP Publishing
Date: 14-04-2011
DOI: 10.1088/0022-3727/44/17/174010
Abstract: Plasma-made nanostructures show outstanding potential for applications in nanotechnology. This paper provides a concise overview on the progress of plasma-based synthesis and applications of silicon nanograss and related nanostructures. The materials described here include black silicon, Si nanotips produced using a self-masking technique as well as self-organized silicon nanocones and nanograss. The distinctive features of the Si nanograss, two-tier hierarchical and tilted nanograss structures are discussed. Specific applications based on the unique features of the silicon nanograss are also presented.
Publisher: Wiley
Date: 21-08-2020
Abstract: Controlled modification of surfaces is one of the key pursuits of the nanoscience and nanotechnology fields, allowing for the fabrication of bespoke materials with targeted functionalities. However, many surface modifications currently require painstakingly precise and/or energy intensive processing to implement, and are thus limited in scope and scale. Here, a concept which can enhance the capacity for control of surfaces is introduced: plasma-assisted nucleation and self-assembly at atomic to nanoscales, scalable at atmospheric pressures.
Publisher: IOP Publishing
Date: 05-02-2018
Publisher: Elsevier BV
Date: 07-2021
Publisher: Wiley
Date: 13-08-2009
Publisher: AIP Publishing
Date: 24-12-2012
DOI: 10.1063/1.4773367
Abstract: Effective control of room-temperature electroluminescence of n-ZnMgO -GaN light-emitting diodes (LEDs) over both emission intensity and wavelength is demonstrated. With varied Mg concentration, the intensity of LEDs in the near-ultraviolet region is increased due to the effective radiative recombination in the ZnMgO layer. Furthermore, the emission wavelength is shifted to the green/yellow spectral region by employing an indium-tin-oxide thin film as the dopant source, where thermally activated indium diffusion creates extra deep defect levels for carrier recombination. These results clearly demonstrate the effectiveness of controlled metal incorporation in achieving high energy efficiency and spectral tunability of the n-ZnMgO -GaN LED devices.
Publisher: Elsevier BV
Date: 10-2015
Publisher: IOP Publishing
Date: 14-04-2011
DOI: 10.1088/0022-3727/44/17/174018
Abstract: Nanoparticles and low-temperature plasmas have been developed, independently and often along different routes, to tackle the same set of challenges in biomedicine. There are intriguing similarities and contrasts in their interactions with cells and living tissues, and these are reflected directly in the characteristics and scope of their intended therapeutic solutions, in particular their chemical reactivity, selectivity against pathogens and cancer cells, safety to healthy cells and tissues and targeted delivery to diseased tissues. Time has come to ask the inevitable question of possible plasma–nanoparticle synergy and the related benefits to the development of effective, selective and safe therapies for modern medicine. This perspective paper offers a detailed review of the strengths and weakenesses of nanomedicine and plasma medicine as a stand-alone technology, and then provides a critical analysis of some of the major opportunities enabled by synergizing nanotechnology and plasma technology. It is shown that the plasma–nanoparticle synergy is best captured through plasma nanotechnology and its benefits for medicine are highly promising.
Publisher: IOP Publishing
Date: 26-04-2019
Abstract: A method for accurate measurements of the size and electron density of open-air plasmas by optical imaging is developed. The plasma size is determined by the intensified charge coupled device (ICCD) imaging and is related to the plasma inductance. The plasma density is then derived from the plasma inductance in open air. The electron densities measured by the ICCD imaging agree well with the reliable Stark broadening method, in stark contrast with the commonly used current–voltage I – method. These shortcomings of the I – method arise because of its heavy reliance on electron mobility values which are uncertain in complex gas mixtures such as air. This work thus presents a new way of using the ICCD imaging to determine the plasma size and electron density and as such contributes to the development of next-generation plasma diagnostic methods.
Publisher: IOP Publishing
Date: 14-04-2011
DOI: 10.1088/0022-3727/44/17/174019
Abstract: The fast advances in nanotechnology have raised increasing concerns related to the safety of nanomaterials when exposed to humans, animals and the environment. However, despite several years of research, the nanomaterials safety field is still in its infancy owing to the complexities of structural and surface properties of these nanomaterials and organism-specific responses to them. Recently, plasma-based technology has been demonstrated as a versatile and effective way for nanofabrication, yet its health and environment-benign nature has not been widely recognized. Here we address the environmental and occupational health and safety effects of various zero- and one-dimensional nanomaterials and elaborate the advantages of using plasmas as a safe nanofabrication tool. These advantages include but are not limited to the production of substrate-bound nanomaterials, the isolation of humans from harmful nanomaterials, and the effective reforming of toxic and flammable gases. It is concluded that plasma nanofabrication can minimize the hazards in the workplace and represents a safe way for future nanofabrication technologies.
Publisher: Wiley
Date: 1994
Publisher: IOP Publishing
Date: 21-06-2011
DOI: 10.1088/0957-4484/22/29/295712
Abstract: Novel nanostructures such as vertically aligned carbon nanotube (CNT) arrays have received increasing interest as drug delivery carriers. In the present study, two CNT arrays with extreme surface wettabilities are fabricated and their effects on the release of recombinant human bone morphogenetic protein-2 (rhBMP-2) are investigated. It is found that the superhydrophilic arrays retained a larger amount of rhBMP-2 than the superhydrophobic ones. Further use of a poloxamer diffusion layer delayed the initial burst and resulted in a greater total amount of rhBMP-2 released from both surfaces. In addition, rhBMP-2 bound to the superhydrophilic CNT arrays remained bioactive while they denatured on the superhydrophobic surfaces. These results are related to the combined effects of rhBMP-2 molecules interacting with poloxamer and the surface, which could be essential in the development of advanced carriers with tailored surface functionalities.
Publisher: AIP Publishing
Date: 06-05-2013
DOI: 10.1063/1.4802885
Abstract: Asymmetrical electrical boundary conditions in (001)-oriented Pb(Zr0.2TiO0.8)O3 (PZT) epitaxial ultrathin ferroelectric films are exploited to control surface photochemical reactivity determined by the sign of the surface polarization charge. It is shown that the preferential orientation of polarization in the as-grown PZT layer can be manipulated by choosing an appropriate type of bottom electrode material. PZT films deposited on the SrRuO3 electrodes exhibit preferential upward polarization (C+) whilst the same films grown on the (La,Sr)CoO3-electrodes are polarized downward (C−). Photochemical activity of the PZT surfaces with different surface polarization charges has been tested by studying deposition of silver nanoparticles from AgNO3 solution under UV irradiation. PZT surfaces with preferential C+ orientation possess a more active surface for metal reduction than their C− counterparts, evidenced by large differences in the concentration of deposited silver nanoparticles. This effect is attributed to band bending at the bottom interface which varies depending on the difference in work functions of PZT and electrode materials.
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1NR06591B
Abstract: Hemostatic agents are pivotal for managing clinical and traumatic bleeding during emergency and domestic circumstances.
Publisher: Elsevier BV
Date: 10-2017
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8TA11374B
Abstract: A novel approach to significantly enhance and comprehensively assess the level of nanochannel ordering in self-assembled nanoporous membranes is proposed and tested.
Publisher: Wiley
Date: 18-12-2020
Abstract: Microplasmas are low-temperature plasmas that feature microscale dimensions and a unique high-energy-density and a nonequilibrium reactive environment, which makes them promising for the fabrication of advanced nanomaterials and devices for erse applications. Here, recent microplasma applications are examined, spanning from high-throughput, printing-technology-compatible synthesis of nanocrystalline particles of common materials types, to water purification and optoelectronic devices. Microplasmas combined with gaseous and/or liquid media at low temperatures and atmospheric pressure open new ways to form advanced functional materials and devices. Specific ex les include gas-phase, substrate-free, plasma-liquid, and surface-supported synthesis of metallic, semiconducting, metal oxide, and carbon-based nanomaterials. Representative applications of microplasmas of particular importance to materials science and technology include light sources for multipurpose, efficient VUV/UV light sources for photochemical materials processing and spectroscopic materials analysis, surface disinfection, water purification, active electromagnetic devices based on artificial microplasma optical materials, and other devices and systems including the plasma transistor. The current limitations and future opportunities for microplasma applications in materials related fields are highlighted.
Publisher: IOP Publishing
Date: 14-04-2011
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4NR04736B
Abstract: The catalytic role of Ge promotes the reversible electrochemical reaction of SnO 2 to Sn, overcoming the limitation of the traditional specific capacity of SnO 2 .
Publisher: IEEE
Date: 06-2013
Publisher: Elsevier BV
Date: 03-1993
Publisher: Elsevier BV
Date: 09-2011
Publisher: Elsevier BV
Date: 05-2018
Publisher: Wiley
Date: 13-08-2019
Publisher: Wiley
Date: 13-08-2019
Publisher: Elsevier BV
Date: 02-2019
DOI: 10.1016/J.JCIS.2019.10.099
Abstract: Electrocatalytic water splitting using bi-functional catalysts is one of the most promising approaches for clean hydrogen fuel production. To address shortcomings of the existing catalysts, here we develop a new bi-functional catalysts cobalt-based nano-architecture with ordered, Ni-doped two-dimensional (2D) defect-rich nanosheets. Innovative combination of doping, annealing, and sulfidation is developed to fabricate the hierarchical porous metal sulfide (denoted as Ni-Co-S) nanosheets arrays (HPNA) directly on conductive carbon cloth (CC). Owing to the unique architecture with the specific surface area and porous structure, short ion diffusion paths, the Ni-Co-S HPNA exhibits excellent electrocatalytic activitiy for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline solution, featuring low overpotentials of 110 and 270 mV at a current density of 10 mA cm
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6TC03871A
Abstract: We describe a simple, efficient plasma-chemical technique for the synthesis of hybrid structures formed by vertically oriented BNCO nanowalls and vertically oriented graphene nanoflakes (BNCONW/GNFs), as well as their structure and photoluminescence properties.
Publisher: IOP Publishing
Date: 14-04-2011
DOI: 10.1088/0022-3727/44/17/174003
Abstract: Plasma nanoscience is an emerging multidisciplinary research field at the cutting edge of a large number of disciplines including but not limited to physics and chemistry of plasmas and gas discharges, materials science, surface science, nanoscience and nanotechnology, solid-state physics, space physics and astrophysics, photonics, optics, plasmonics, spintronics, quantum information, physical chemistry, biomedical sciences and related engineering subjects. This paper examines the origin, progress and future perspectives of this research field driven by the global scientific and societal challenges. The future potential of plasma nanoscience to remain a highly topical area in the global research and technological agenda in the age of fundamental-level control for a sustainable future is assessed using a framework of the five Grand Challenges for Basic Energy Sciences recently mapped by the US Department of Energy. It is concluded that the ongoing research is very relevant and is expected to substantially expand to competitively contribute to the solution of all of these Grand Challenges. The approach to controlling energy and matter at nano- and subnanoscales is based on identifying the prevailing carriers and transfer mechanisms of the energy and matter at the spatial and temporal scales that are most relevant to any particular nanofabrication process. Strong accent is made on the competitive edge of the plasma-based nanotechnology in applications related to the major socio-economic issues (energy, food, water, health and environment) that are crucial for a sustainable development of humankind. Several important emerging topics, opportunities and multidisciplinary synergies for plasma nanoscience are highlighted. The main nanosafety issues are also discussed and the environment- and human health-friendly features of plasma-based nanotech are emphasized.
Publisher: Elsevier BV
Date: 2016
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C6NH00167J
Abstract: An effective, dry-climate natural plant-inspired approach for controlled surface engineering and liquid–solid interactions within graphene-based sub-micrometer confined spaces.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2009
Publisher: IOP Publishing
Date: 17-12-2020
Publisher: Elsevier BV
Date: 02-2022
Publisher: American Chemical Society (ACS)
Date: 09-04-2020
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2011
Publisher: American Chemical Society (ACS)
Date: 09-10-2023
Publisher: Elsevier BV
Date: 02-2022
DOI: 10.1016/J.TIG.2021.09.009
Abstract: Histone lactylation and acetylation compete for epigenetic modification of lysines and mark the levels of lactates and acetyl-CoA. Whether pyruvate is committed to lactate or acetyl-CoA generation as the outlet of glycolysis determines cell fate towards malignancy or not. Taking control over the glycolytic switch as marked by lactylation suggests novel therapeutic opportunities against cancers.
Publisher: Elsevier BV
Date: 11-2021
Publisher: MDPI AG
Date: 05-08-2015
DOI: 10.3390/MA8084992
Publisher: Elsevier BV
Date: 08-2009
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1NR01937F
Abstract: ITO nanotubes and NTrees produced by a one reactor combination of industrially scalable vacuum and plasma protocols with outstanding properties as random optical media and ultra-broadband perfect absorbers and low resistivity at macro and nanoscales.
Publisher: Springer Science and Business Media LLC
Date: 24-11-2020
DOI: 10.1038/S41467-020-19766-X
Abstract: Two-dimensional (2D) atomic crystal superlattices integrate erse 2D layered materials enabling adjustable electronic and optical properties. However, tunability of the interlayer gap and interactions remain challenging. Here we report a solution based on soft oxygen plasma intercalation. 2D atomic crystal molecular superlattices (ACMSs) are produced by intercalating O 2 + ions into the interlayer space using the plasma electric field. Stable molecular oxygen layer is formed by van der Waals interactions with adjacent transition metal dichalcogenide (TMD) monolayers. The resulting interlayer gap expansion can effectively isolate TMD monolayers and impart exotic properties to homo-(MoS 2 [O 2 ] x ) and hetero-(MoS 2 [O 2 ] x /WS 2 [O 2 ] x ) stacked ACMSs beyond typical capacities of monolayer TMDs, such as 100 times stronger photoluminescence and 100 times higher photocurrent. Our potentially universal approach to tune interlayer stacking and interactions in 2D ACMSs may lead to exotic superlattice properties intrinsic to monolayer materials such as direct bandgap pursued for future optoelectronics.
Publisher: American Chemical Society (ACS)
Date: 13-07-2021
Publisher: Elsevier BV
Date: 10-2004
Publisher: AIP Publishing
Date: 04-11-2019
DOI: 10.1063/1.5120109
Abstract: Homogeneous penetration of atmospheric pressure uniform air plasma (APUAP) into thin gaps is highly warranted for multipurpose processing of materials. Here, we report APUAP generation in a 7 mm discharge gap with ambient air as the working gas, well beyond the presently maximum achievable 4 mm. Driven by a short pulse high voltage power, a 7 mm wide and 60 mm long uniform air plasma sheet is generated. The discharge is robust and the uniformity is not affected by the complex and variable components of ambient air, as is the case for most plasma discharges in air. Ultrafast photography shows that, different from previous reports, the discharge initiates in the whole air gap simultaneously and brightens quickly with the fast rise of the pulsed voltage. The generation of uniform plasma is mainly attributed to the high density of seed electrons and the reduced number density of molecules in air. Moreover, the achievable gas temperature of up to 1300 K indicates that this type of plasma is suitable for processing of a broad range of materials.
Publisher: Elsevier BV
Date: 12-2020
Publisher: Springer Science and Business Media LLC
Date: 03-06-2009
Publisher: IOP Publishing
Date: 31-01-2019
Publisher: American Chemical Society (ACS)
Date: 30-12-2016
DOI: 10.1021/ACS.CHEMREV.5B00566
Abstract: Sustainable societal and economic development relies on novel nanotechnologies that offer maximum efficiency at minimal environmental cost. Yet, it is very challenging to apply green chemistry approaches across the entire life cycle of nanotech products, from design and nanomaterial synthesis to utilization and disposal. Recently, novel, efficient methods based on nonequilibrium reactive plasma chemistries that minimize the process steps and dramatically reduce the use of expensive and hazardous reagents have been applied to low-cost natural and waste sources to produce value-added nanomaterials with a wide range of applications. This review discusses the distinctive effects of nonequilibrium reactive chemistries and how these effects can aid and advance the integration of sustainable chemistry into each stage of nanotech product life. Ex les of the use of enabling plasma-based technologies in sustainable production and degradation of nanotech products are discussed-from selection of precursors derived from natural resources and their conversion into functional building units, to methods for green synthesis of useful naturally degradable carbon-based nanomaterials, to device operation and eventual disintegration into naturally degradable yet potentially reusable byproducts.
Publisher: American Chemical Society (ACS)
Date: 27-06-2022
Publisher: American Chemical Society (ACS)
Date: 22-12-2022
Abstract: Functionally graded materials (FGMs) exhibit unique properties and are expected to deliver outstanding and stable performance under extreme conditions. High-voltage, high-power FGM-based electric insulation commonly fails because of inadequate surface charge control (flashover) performance and stability of stacked layers of dielectric materials with graded permittivity ε
Publisher: AIP Publishing
Date: 07-2001
DOI: 10.1063/1.1375149
Abstract: Charging and trapping of macroparticles in the near-electrode region of fluorocarbon etching plasmas with negative ions is considered. The equilibrium charge and forces on particles are computed as a function of the local position in the plasma presheath and sheath. The ionic composition of the plasma corresponds to the etching experiments in 2.45 GHz surface-wave sustained and 13.56 MHz inductively coupled C4F8+Ar plasmas. It is shown that despite negligible negative ion currents collected by the particles, the negative fluorine ions affect the charging and trapping of particulates through modification of the sheath resheath structure.
Publisher: AIP Publishing
Date: 10-06-2013
DOI: 10.1063/1.4811165
Abstract: Palladium is sputtered on multi-walled carbon nanotube forests to form carbon-metal core-shell nanowire arrays. These hybrid nanostructures exhibited resistive responses when exposed to hydrogen with an excellent baseline recovery at room temperature. The magnitude of the response is shown to be tuneable by an applied voltage. Unlike the charge-transfer mechanism commonly attributed to Pd nanoparticle-decorated carbon nanotubes, this demonstrates that the hydrogen response mechanism of the multi-walled carbon nanotube-Pd core-shell nanostructure is due to the increase in electron scattering induced by physisorption of hydrogen. These hybrid core-shell nanostructures are promising for gas detection in hydrogen storage applications.
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D1GC03859A
Abstract: Sustainable plasma-driven N 2 oxidation for NO x formation by a nanosecond pulsed spark discharge is proposed to approach the zero-carbon emissions target with new insights into free-radical-chain reactions by kinetics modeling and optical diagnosis.
Publisher: Elsevier BV
Date: 10-2018
Publisher: Springer Science and Business Media LLC
Date: 22-05-2015
Publisher: Oxford University Press (OUP)
Date: 04-11-2020
Abstract: In this work, we combine spectroscopic information from the SkyMapper survey for Extremely Metal-Poor stars and astrometry from Gaia DR2 to investigate the kinematics of a s le of 475 stars with a metallicity range of $-6.5 \le \rm [Fe/H] \le -2.05$ dex. Exploiting the action map, we identify 16 and 40 stars dynamically consistent with the Gaia Sausage and Gaia Sequoia accretion events, respectively. The most metal poor of these candidates have metallicities of $\rm [Fe/H]=-3.31\, \mathrm{ and }\, -3.74$, respectively, helping to define the low-metallicity tail of the progenitors involved in the accretion events. We also find, consistent with other studies, that ∼21 per cent of the s le have orbits that remain confined to within 3 kpc of the Galactic plane, that is, |Zmax| ≤ 3 kpc. Of particular interest is a subs le (∼11 per cent of the total) of low |Zmax| stars with low eccentricities and prograde motions. The lowest metallicity of these stars has [Fe/H] = –4.30 and the subs le is best interpreted as the very low-metallicity tail of the metal-weak thick disc population. The low |Zmax|, low eccentricity stars with retrograde orbits are likely accreted, while the low |Zmax|, high eccentricity pro- and retrograde stars are plausibly associated with the Gaia Sausage system. We find that a small fraction of our s le (∼4 per cent of the total) is likely escaping from the Galaxy, and postulate that these stars have gained energy from gravitational interactions that occur when infalling dwarf galaxies are tidally disrupted.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9TC01808E
Abstract: A direct one-step nano-gold printing process from a HAuCl 4 solution precursor is demonstrated using an atmospheric-pressure plasma jet.
Publisher: Springer Science and Business Media LLC
Date: 18-02-2021
Publisher: Wiley
Date: 24-08-2021
Abstract: Peroxynitrite is an important chemical in the human immune system, which has high biocidal activity and can resist the invasion of pathogens. Currently, in vitro generation of peroxynitrite faces major technological challenges, especially for gas‐phase production, which requires low‐pressure conditions. Here, we report the method of how to generate gas‐phase peroxynitrite at atmospheric pressure using dielectric barrier discharge. Results show that the peroxynitrite concentration positively correlates with energy density. Moreover, Penicillium digitatum , a common fungus contaminant greatly affecting food and fruit preservation, was used as a microbial pathogen model to confirm the biocidal effects of ozone‐free nitrogen oxides under different discharge conditions. The germination inhibition efficiency of P. digitatum is highly likely attributed to the synergistic effect of gaseous peroxynitrite and NO.
Publisher: Elsevier BV
Date: 2022
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-2013
Publisher: Elsevier BV
Date: 04-2022
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2GC02299K
Abstract: This work demonstrates alternative green ammonia processing using nitrogen and water based non-thermal plasma without pure hydrogen supply which results in an enormous amount of CO 2 emission.
Publisher: Springer Science and Business Media LLC
Date: 10-03-2009
Publisher: Elsevier BV
Date: 12-2010
Publisher: SPIE
Date: 28-12-2006
DOI: 10.1117/12.638237
Publisher: Royal Society of Chemistry (RSC)
Date: 2009
DOI: 10.1039/B904227J
Publisher: SPIE
Date: 28-12-2006
DOI: 10.1117/12.638235
Publisher: SPIE
Date: 28-12-2006
DOI: 10.1117/12.638236
Publisher: AIP Publishing
Date: 05-04-2011
DOI: 10.1063/1.3560509
Abstract: The approach to control the elementary processes of plasma–surface interactions to direct the fluxes of energy and matter at nano- and subnanometer scales is introduced. This ability is related to the solution of the grand challenge of directing energy and matter at nanoscales and is critical for the renewable energy and energy-efficient technologies for a sustainable future development. The ex les of deterministic synthesis of self-organized arrays of metastable nanostructures in the size range beyond the reach of the present-day nanofabrication are considered to illustrate this possibility. By using precisely controlled and kinetically fast nanoscale transfer of energy and matter under nonequilibrium conditions and harnessing numerous plasma-specific controls of species creation, delivery to the surface, nucleation, and large-scale self-organization of nuclei and nanostructures, the arrays of metastable nanostructures can be created, arranged, stabilized, and further processed to meet the specific requirements of the envisaged applications.
Publisher: IEEE
Date: 07-2016
Publisher: Royal Society of Chemistry (RSC)
Date: 2010
DOI: 10.1039/C0JM01060J
Publisher: AIP Publishing
Date: 11-03-2020
DOI: 10.1063/1.3673593
Abstract: An advanced inductively coupled plasma (ICP)-assisted rf magnetron sputtering deposition method is developed to synthesize regular arrays of pear-shaped ZnO nanodots on a thin SiNx buffer layer pre-deposited onto a silicon substrate. It is shown that the growth of ZnO nanodots obey the cubic root-law behavior. It is also shown that the synthesized ZnO nanodots are highly-uniform, controllable by the experimental parameters, and also feature good structural and photoluminescent properties. These results suggest that this custom-designed ICP-based technique is very effective and highly-promising for the synthesis of property- and size-controllable highly-uniform ZnO nanodots suitable for next-generation light emitting diodes, energy storage, UV nanolasers, and other applications.
Publisher: Elsevier BV
Date: 09-2020
Publisher: Springer Science and Business Media LLC
Date: 02-02-2013
Publisher: Elsevier BV
Date: 09-2018
Publisher: Wiley
Date: 09-2021
Publisher: Elsevier BV
Date: 05-2009
Publisher: AIP Publishing
Date: 31-03-2008
DOI: 10.1063/1.2905265
Abstract: The response of an originally developed catalytic sensor with a Nb2O5 nanowire array at its outer surface to the varying density of O atoms is experimentally and numerically studied. This technique can be used to measure one order of magnitude lower densities of O atoms and achieve a stable linear response in a significantly broader pressure range compared to conventional catalytic probes with a flat surface. The nanostructured outer surface also acts as a thermal barrier against sensor overheating. This approach is generic and can be used for reactive species detection in other reactive gas environments.
Publisher: IOP Publishing
Date: 06-12-2021
Abstract: Minimizing the breakdown voltage and discharge current required to initiate direct in-liquid discharges, thus lowering power-source requirements and avoiding electrode ablation, is crucial for industrial applications of in-liquid plasmas. Here we demonstrate such considerable reductions by employing movable electrodes, without changing the electrode configuration or increasing the system complexity. The new mechanism is based on electrostatic electrode attraction resulting in a reduction in the discharge spacing by up to 6 times and facilitating a plasma initiation at lower breakdown voltages. The accumulated charges consumed by the discharge revert the electrodes to the initial positions, forming a gliding arc between the enlarged gaps and thus inhibiting current increases and electrode ablation.
Publisher: IOP Publishing
Date: 04-04-2012
DOI: 10.1088/0022-3727/45/16/165205
Abstract: Effective biofilm inactivation using a handheld, mobile plasma jet powered by a 12 V dc battery and operated in open air without any external gas supply is reported. This cold, room-temperature plasma is produced in self-repetitive nanosecond discharges with current pulses of ∼100 ns duration, current peak litude of ∼6 mA and repetition rate of ∼20 kHz. It is shown that the reactive plasma species penetrate to the bottom layer of a 25.5 µm-thick Enterococcus faecalis biofilm and produce a strong bactericidal effect. This is the thickest reported biofilm inactivated using room-temperature air plasmas.
Publisher: AIP Publishing
Date: 11-02-2008
DOI: 10.1063/1.2841845
Abstract: It is shown that the simultaneous saturation of Ni nanoparticles used as catalyst for vertically aligned carbon nanotube and nanocone arrays can be improved in low-temperature plasma- or ion-assisted processes compared with neutral gas-based routes. The results of hybrid multiscale numerical simulations of the catalyst nanoarrays (particle sizes of 2 and 10nm) saturation with carbon show the possibility of reducing the difference in catalyst incubation times for smallest and largest catalyst particles by up to a factor of 2. This approach is generic and provides process conditions for simultaneous nucleation and growth of uniform arrays of vertically aligned nanostructures.
Publisher: Elsevier BV
Date: 05-2022
Publisher: American Chemical Society (ACS)
Date: 28-10-2020
Publisher: Elsevier BV
Date: 11-2015
Publisher: Elsevier BV
Date: 05-2015
Publisher: Elsevier BV
Date: 04-2022
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1NR03917B
Abstract: We develop a soft plasma doping concept and demonstrate both n-type and p-type doping for TMDs through adjusting the plasma working parameters. This generic method may be used as a reliable technology for the development of TMD-based devices.
Publisher: Elsevier BV
Date: 04-2018
Publisher: The Electrochemical Society
Date: 21-11-2007
DOI: 10.1149/1.2812901
Abstract: Experimentally observed optical and photoelectrical spectra of nitrogen-contaminated (unintentionally doped) nano-crystalline CVD diamond films are simulated using semi-empirical adiabatic General Skettrup Model (GSM), which presumes dominant contributions of defect states from sp3-coordinated intra- granular carbon atoms to intra-band single electron spectrum N(E) of the material. This picture disagrees with a common viewpoint that the N(E) spectrum of the gap states in diamond powders and polycrystalline CVD films mainly originates from p and p* bonds of sp2-coordinated carbon atoms, which are distributed nearly uniformly over outer surfaces and/or interfaces of the diamond grains. The GSM predicts as well strong effect of granular morphology on the density of intra- band defect states in polycrystalline diamonds.
Publisher: Institution of Engineering and Technology (IET)
Date: 30-01-2022
DOI: 10.1049/HVE2.12189
Publisher: IEEE
Date: 07-2012
Publisher: American Chemical Society (ACS)
Date: 25-01-2023
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D0NH00598C
Abstract: Predicted ferromagnetic FeB 3 monolayer simultaneously possesses the high transition temperature and large perpendicular anisotropy, leading to great potentials in highly efficient spintronic applications.
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C4RA08187K
Abstract: Vertically-aligned carbon nanotube arrays treated with inductively-coupled plasmas demonstrate selective support of biofilms of Gram-negative and Gram-positive bacteria.
Publisher: IOP Publishing
Date: 21-08-2008
DOI: 10.1088/0957-4484/19/40/405605
Abstract: Plasma-assisted synthesis of nanostructures is one of the most precise and effective approaches used in nanodevice fabrication. Here we report on the innovative approach of synthesizing nanostructured cadmium oxide films on Cd substrates using a reactive oxygen plasma-based process. Under certain conditions, the surface morphology features arrays of crystalline CdO nano/micropyramids. These nanostructures grow via unconventional plasma-assisted oxidation of a cadmium foil exposed to inductively coupled plasmas with a narrow range of process parameters. The growth of the CdO pyramidal nanostructures takes place in the solid-liquid-solid phase, with the rates determined by the interaction of plasma-produced oxygen atoms and ions with the surface. It is shown that the size of the pyramidal structures can be effectively controlled by the fluxes of oxygen atoms and ions impinging on the cadmium surface. The unique role of the reactive plasma environment in the controlled synthesis of CdO nanopyramidal structures is discussed as well.
Publisher: No publisher found
Date: 2020
Publisher: AIP Publishing
Date: 19-12-2011
DOI: 10.1063/1.3666819
Abstract: The Ar/O2 plasma needle in the induction of A549 cancer cells apoptosis process is studied by means of real-time observation. The entire process of programmed cell death is observed. The typical morphological changes of A549 apoptosis are detected by 4′, 6-diamidino-2-phenylindole staining, for ex le, chromatin condensation and nuclear fragmentation. Cell viability is determined and quantified by neutral red uptake assay, and the survival rate of A549 from Ar/O2 plasmas is presented. Further spectral analysis indicates the reactive species, including O and OH play crucial roles in the cell inactivation.
Publisher: American Chemical Society (ACS)
Date: 19-09-2019
Abstract: Designing high efficient and noble metal-free bifunctional electrocatalysts for both hydrogen and oxygen generation is still critical and challenged. In this study, hierarchical dodecahedral-structured CoP/CN@MoS
Publisher: Elsevier
Date: 2016
Publisher: Elsevier BV
Date: 07-2007
Publisher: AIP Publishing
Date: 10-2012
DOI: 10.1063/1.4762858
Abstract: Atmospheric-pressure plasma jets are commonly used in many fields from medicine to nanotechnology, yet the issue of scaling the discharges up to larger areas without compromising the plasma uniformity remains a major challenge. In this paper, we demonstrate a homogenous cold air plasma glow with a large cross-section generated by a direct current power supply. There is no risk of glow-to-arc transitions, and the plasma glow appears uniform regardless of the gap between the nozzle and the surface being processed. Detailed studies show that both the position of the quartz tube and the gas flow rate can be used to control the plasma properties. Further investigation indicates that the residual charges trapped on the inner surface of the quartz tube may be responsible for the generation of the air plasma plume with a large cross-section. The spatially resolved optical emission spectroscopy reveals that the air plasma plume is uniform as it propagates out of the nozzle. The remarkable improvement of the plasma uniformity is used to improve the bio-compatibility of a glass coverslip over a reasonably large area. This improvement is demonstrated by a much more uniform and effective attachment and proliferation of human embryonic kidney 293 (HEK 293) cells on the plasma-treated surface.
Publisher: AIP Publishing
Date: 10-2012
DOI: 10.1063/1.4757022
Abstract: The effect of a magnetic field of two magnetic coils on the ion current density distribution in the setup for low-temperature plasma deposition is investigated. The substrate of 400 mm diameter is placed at a distance of 325 mm from the plasma duct exit, with the two magnetic coils mounted symmetrically under the substrate at a distance of 140 mm relative to the substrate centre. A planar probe is used to measure the ion current density distribution along the plasma flux cross-sections at distances of 150, 230, and 325 mm from the plasma duct exit. It is shown that the magnetic field strongly affects the ion current density distribution. Transparent plastic films are used to investigate qualitatively the ion density distribution profiles and the effect of the magnetic field. A theoretical model is developed to describe the interaction of the ion fluxes with the negative space charge regions associated with the magnetic trapping of the plasma electrons. Theoretical results are compared with the experimental measurements, and a reasonable agreement is demonstrated.
Publisher: Elsevier BV
Date: 12-2021
Publisher: Elsevier BV
Date: 09-2014
DOI: 10.1016/J.CHROMA.2014.07.052
Abstract: Single-walled carbon nanotubes were encapsulated into different polymer-based monolithic backbones. The polymer monoliths were prepared via the copolymerization of 20% monomers, glycidyl methacrylate, 20% ethylene glycol dimethacrylate and 60% porogens (36% 1-propanol, 18% 1,4-butanediol) or 16.4% monomers (16% butyl methacrylate, 0.4% sulfopropyl methacrylate), 23.6% ethylene glycol dimethacrylate and 60% porogens (36% 1-propanol, 18% 1,4-butanediol) along with 6% single-walled carbon nanotubes aqueous suspension. The effect of single-walled carbon nanotubes on the chiral separation of twelve classes of pharmaceutical racemates namely α- and β-blockers, antiinflammatory drugs, antifungal drugs, dopamine antagonists, norepinephrine-dopamine reuptake inhibitors, catecholamines, sedative hypnotics, diuretics, antihistaminics, anticancer drugs and antiarrhythmic drugs was investigated. The enantioselective separation was carried out under multimodal elution to explore the chiral recognition capabilities of single-walled carbon nanotubes using reversed phase, polar organic and normal phase chromatographic conditions using nano-liquid chromatography. Baseline separation was achieved for celiprolol, chlorpheniramine, etozoline, nomifensine and sulconazole under multimodal elution conditions. Satisfactory repeatability was achieved through run-to-run, column-to-column and batch-to-batch investigations. Our findings demonstrate that single-walled carbon nanotubes represent a promising stationary phase for the chiral separation and may open the field for a new class of chiral selectors.
Publisher: American Chemical Society (ACS)
Date: 24-06-2019
Publisher: American Chemical Society (ACS)
Date: 09-01-2020
Publisher: Elsevier BV
Date: 09-2020
Publisher: American Chemical Society (ACS)
Date: 30-11-2015
DOI: 10.1021/ACS.CHEMREV.5B00362
Abstract: Thermal-catalytic gas processing is integral to many current industrial processes. Ever-increasing demands on conversion and energy efficiencies are a strong driving force for the development of alternative approaches. Similarly, synthesis of several functional materials (such as nanowires and nanotubes) demands special processing conditions. Plasma catalysis provides such an alternative, where the catalytic process is complemented by the use of plasmas that activate the source gas. This combination is often observed to result in a synergy between plasma and catalyst. This Review introduces the current state-of-the-art in plasma catalysis, including numerous ex les where plasma catalysis has demonstrated its benefits or shows future potential, including CO2 conversion, hydrocarbon reforming, synthesis of nanomaterials, ammonia production, and abatement of toxic waste gases. The underlying mechanisms governing these applications, as resulting from the interaction between the plasma and the catalyst, render the process highly complex, and little is known about the factors leading to the often-observed synergy. This Review critically examines the catalytic mechanisms relevant to each specific application.
Publisher: Elsevier BV
Date: 03-2021
Publisher: IOP Publishing
Date: 11-03-2021
Publisher: American Chemical Society (ACS)
Date: 21-01-2021
Publisher: Elsevier BV
Date: 02-2021
Publisher: IOP Publishing
Date: 14-05-2014
Publisher: American Society for Cell Biology (ASCB)
Date: 05-2014
Abstract: Atmospheric gas plasmas (AGPs) are able to selectively induce apoptosis in cancer cells, offering a promising alternative to conventional therapies that have unwanted side effects such as drug resistance and toxicity. However, the mechanism of AGP-induced cancer cell death is unknown. In this study, AGP is shown to up-regulate intracellular reactive oxygen species (ROS) levels and induce apoptosis in melanoma but not normal melanocyte cells. By screening genes involved in apoptosis, we identify tumor necrosis factor (TNF)–family members as the most differentially expressed cellular genes upon AGP treatment of melanoma cells. TNF receptor 1 (TNFR1) antagonist–neutralizing antibody specifically inhibits AGP-induced apoptosis signal, regulating apoptosis signal–regulating kinase 1 (ASK1) activity and subsequent ASK1-dependent apoptosis. Treatment of cells with intracellular ROS scavenger N-acetyl-l-cysteine also inhibits AGP-induced activation of ASK1, as well as apoptosis. Moreover, depletion of intracellular ASK1 reduces the level of AGP-induced oxidative stress and apoptosis. The evidence for TNF-signaling dependence of ASK1-mediated apoptosis suggests possible mechanisms for AGP activation and regulation of apoptosis-signaling pathways in tumor cells.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-2011
Publisher: Springer Science and Business Media LLC
Date: 13-11-2021
DOI: 10.1007/S40820-020-00545-8
Abstract: Solar-driven photoelectrochemical (PEC) water splitting systems are highly promising for converting solar energy into clean and sustainable chemical energy. In such PEC systems, an integrated photoelectrode incorporates a light harvester for absorbing solar energy, an interlayer for transporting photogenerated charge carriers, and a co-catalyst for triggering redox reactions. Thus, understanding the correlations between the intrinsic structural properties and functions of the photoelectrodes is crucial. Here we critically examine various 2D layered photoanodes hotocathodes, including graphitic carbon nitrides, transition metal dichalcogenides, layered double hydroxides, layered bismuth oxyhalide nanosheets, and MXenes, combined with advanced nanocarbons (carbon dots, carbon nanotubes, graphene, and graphdiyne) as co-catalysts to assemble integrated photoelectrodes for oxygen evolution/hydrogen evolution reactions. The fundamental principles of PEC water splitting and physicochemical properties of photoelectrodes and the associated catalytic reactions are analyzed. Elaborate strategies for the assembly of 2D photoelectrodes with nanocarbons to enhance the PEC performances are introduced. The mechanisms of interplay of 2D photoelectrodes and nanocarbon co-catalysts are further discussed. The challenges and opportunities in the field are identified to guide future research for maximizing the conversion efficiency of PEC water splitting.
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C4RA17244B
Abstract: This article reviews antibacterial surface strategies based on reactive plasma chemistry, focusing on how plasma-assisted processing of natural antimicrobial agents can produce antifouling and antibacterial materials for biomedical devices.
Publisher: Wiley
Date: 02-06-2005
Publisher: IOP Publishing
Date: 13-06-2008
Publisher: IEEE
Date: 12-2012
Publisher: AIP Publishing
Date: 05-2007
DOI: 10.1063/1.2727448
Abstract: Self-assembly of size-uniform and spatially ordered quantum dot (QD) arrays is one of the major challenges in the development of the new generation of semiconducting nanoelectronic and photonic devices. Assembly of Ge QD (in the ∼5−20 nm size range) arrays from randomly generated position and size-nonuniform nanodot patterns on plasma-exposed Si(100) surfaces is studied using hybrid multiscale numerical simulations. It is shown, by properly manipulating the incoming ion/neutral flux from the plasma and the surface temperature, the uniformity of the nanodot size within the array can be improved by 34%−53%, with the best improvement achieved at low surface temperatures and high external incoming fluxes, which are intrinsic to plasma-aided processes. Using a plasma-based process also leads to an improvement (∼22% at 700 K surface temperature and 0.1 ML∕s incoming flux from the plasma) of the spatial order of a randomly s led nanodot ensemble, which self-organizes to position the dots equidistantly to their neighbors within the array. Remarkable improvements in QD ordering and size uniformity can be achieved at high growth rates (a few nm∕s) and a surface temperature as low as 600 K, which broadens the range of suitable substrates to temperature-sensitive ultrathin nanofilms and polymers. The results of this study are generic, can also be applied to nonplasma-based techniques, and as such contributes to the development of deterministic strategies of nanoassembly of self-ordered arrays of size-uniform QDs, in the size range where nanodot ordering cannot be achieved by presently available pattern delineation techniques.
Publisher: Elsevier BV
Date: 06-2009
Publisher: American Chemical Society (ACS)
Date: 29-10-2012
DOI: 10.1021/NN3041446
Abstract: Graphene grown on metal catalysts with low carbon solubility is a highly competitive alternative to exfoliated and other forms of graphene, yet a single-layer, single-crystal structure remains a challenge because of the large number of randomly oriented nuclei that form grain boundaries when stitched together. A kinetic model of graphene nucleation and growth is developed to elucidate the effective controls of the graphene island density and surface coverage from the onset of nucleation to the full monolayer formation in low-pressure, low-temperature CVD. The model unprecedentedly involves the complete cycle of the elementary gas-phase and surface processes and shows a precise quantitative agreement with the recent low-energy electron diffraction measurements and also explains numerous parameter trends from a host of experimental reports. These agreements are demonstrated for a broad pressure range as well as different combinations of precursor gases and supporting catalysts. The critical role of hydrogen in controlling the graphene nucleation and monolayer formation is revealed and quantified. The model is generic and can be extended to even broader ranges of catalysts and precursor gases ressures to enable the as yet elusive effective control of the crystalline structure and number of layers of graphene using the minimum amounts of matter and energy.
Publisher: AIP Publishing
Date: 08-2013
DOI: 10.1063/1.4817954
Abstract: Two kinds of floating electrode, floating dielectric barrier covered electrode (FDBCE) and floating pin electrode (FPE), which can enhance the performance of plasma jet are reported. The intense discharge between the floating electrode and power electrode decreased the voltage to trigger the plasma jet substantially. The transition of plasma bullet from ring shape to disk shape in the high helium concentration region happened when the floating electrode was totally inside the powered ring electrode. The enhanced electric field between propagating plasma bullet and ground electrode is the reason for this transition. The double plasma bullets happened when part of the FDBCE was outside the powered ring electrode, which is attributed to the structure and surface charge of FDBCE. As part of the FPE was outside the powered ring electrode, the return stroke resulted in a single intensified plasma channel between FPE and ground electrode.
Publisher: AIP Publishing
Date: 10-2008
DOI: 10.1063/1.2996272
Abstract: The kinetics of the nucleation and growth of carbon nanotube and nanocone arrays on Ni catalyst nanoparticles on a silicon surface exposed to a low-temperature plasma are investigated numerically, using a complex model that includes surface diffusion and ion motion equations. It is found that the degree of ionization of the carbon flux strongly affects the kinetics of nanotube and nanocone nucleation on partially saturated catalyst patterns. The use of highly ionized carbon flux allows formation of a nanotube array with a very narrow height distribution of half-width 7 nm. Similar results are obtained for carbon nanocone arrays, with an even narrower height distribution, using a highly ionized carbon flux. As the deposition time increases, nanostructure arrays develop without widening the height distribution when the flux ionization degree is high, in contrast to the fairly broad nanostructure height distributions obtained when the degree of ionization is low.
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5TA03012A
Abstract: Supercapacitor electrodes assembled from meso/macroporous c hor-derived carbon sponges show highly promising performance in ac line-filtering.
Publisher: Elsevier BV
Date: 12-2021
Publisher: American Chemical Society (ACS)
Date: 15-02-2021
Publisher: Springer Science and Business Media LLC
Date: 02-07-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C1NR10765H
Abstract: Tailoring the density of random single-walled carbon nanotube (SWCNT) networks is of paramount importance for various applications, yet it remains a major challenge due to the insufficient catalyst activation in most growth processes. Here we report on a simple and effective method to maximise the number of active catalyst nanoparticles using catalytic chemical vapor deposition (CCVD). By modulating short pulses of acetylene into a methane-based CCVD growth process, the density of SWCNTs is dramatically increased by up to three orders of magnitude without increasing the catalyst density and degrading the nanotube quality. In the framework of a vapor-liquid-solid model, we attribute the enhanced growth to the high dissociation rate of acetylene at high temperatures at the nucleation stage, which can be effective in both supersaturating the larger catalyst nanoparticles and overcoming the nanotube nucleation energy barrier of the smaller catalyst nanoparticles. These results are highly relevant to numerous applications of random SWCNT networks in next-generation energy, sensing and biomedical devices.
Publisher: MDPI AG
Date: 20-05-2015
DOI: 10.3390/NANO5020826
Publisher: Optica Publishing Group
Date: 03-06-2009
DOI: 10.1364/OE.17.010195
Abstract: Recent research in the rapidly emerging field of plasmonics has shown the potential to significantly enhance light trapping inside thin-film solar cells by using metallic nanoparticles. In this article it is demonstrated the plasmon enhancement of optical absorption in amorphous silicon solar cells by using silver nanoparticles. Based on the analysis of the higher-order surface plasmon modes, it is shown how spectral positions of the surface plasmons affect the plasmonic enhancement of thin-film solar cells. By using the predictive 3D modeling, we investigate the effect of the higher-order modes on that enhancement. Finally, we suggest how to maximize the light trapping and optical absorption in the thin-film cell by optimizing the nanoparticle array parameters, which in turn can be used to fine tune the corresponding surface plasmon modes.
Publisher: American Physical Society (APS)
Date: 14-02-2005
Publisher: IOP Publishing
Date: 02-02-2007
Publisher: AIP Publishing
Date: 03-2008
DOI: 10.1063/1.2884531
Abstract: The effect of the film thickness and postannealing temperature on visible photoluminescence (PL) from SiNx films synthesized by plasma-assisted radio frequency magnetron sputtering on SiO2 buffer layers is investigated. It is shown that strong visible PL is achieved at annealing temperatures above 650°C. The optimum annealing temperature for the maximum PL yield strongly depends on the film thickness and varies from 800to1200°C. A comparative composition-structure-property analysis reveals that the PL intensity is directly related to the content of the Si–O and Si–N bonds in the SiNx films. Therefore, sufficient oxidation and moderate nitridation of SiNx∕SiO2 films during the plasma-based growth process are crucial for a strong PL yield. Excessively high annealing temperatures lead to weakened Si–N bonds in thinner SiNx films, which eventually results in a lower PL intensity.
Publisher: Elsevier BV
Date: 2021
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-1995
DOI: 10.1109/2944.401211
Publisher: IOP Publishing
Date: 26-08-2009
DOI: 10.1088/0957-4484/20/37/375603
Abstract: The results of large-scale ( approximately 10(9) atoms) numerical simulations of the growth of different-diameter vertically-aligned single-walled carbon nanotubes in plasma systems with different sheath widths and in neutral gases with the same operating parameters are reported. It is shown that the nanotube lengths and growth rates can be effectively controlled by varying the process conditions. The SWCNT growth rates in the plasma can be up to two orders of magnitude higher than in the equivalent neutral gas systems. Under specific process conditions, thin SWCNTs can grow much faster than their thicker counterparts despite the higher energies required for catalyst activation and nanotube nucleation. This selective growth of thin SWCNTs opens new avenues for the solution of the currently intractable problem of simultaneous control of the nanotube chirality and length during the growth stage.
Publisher: Elsevier BV
Date: 2021
Publisher: AIP Publishing
Date: 29-12-2008
DOI: 10.1063/1.3058766
Abstract: Large-scale (∼109 atoms) numerical simulations reveal that plasma-controlled dynamic delivery and redistribution of carbon atoms between the substrate and nanotube surfaces enable the growth of ultralong single walled carbon nanotubes (SWCNTs) and explain the common experimental observation of slower growth at advanced stages. It is shown that the plasma-based processes feature up to two orders of magnitude higher growth rates than equivalent neutral-gas systems and are better suited for the SWCNT synthesis at low nanodevice friendly temperatures.
Publisher: Elsevier BV
Date: 05-2016
Publisher: IOP Publishing
Date: 12-10-2021
Abstract: Some advances have been achieved in developing heterojunctions consisting of indium-gallium-zinc oxide (a-IGZO) films and two dimensional (2D) van der Waals materials for optoelectronic applications in recent years, however, the improvement of IGZO channel itself via constructing such heterojunctions is rarely reported. Here, we report the huge improvement in photoresponse performances for the IGZO phototransistor devices by introducing boron nitride (BN)/black phosphorus (BP) interface engineering. By creating an appropriate band bending and an efficient photo-generated carrier transfer path between IGZO and BP, the recombination of the photo-generated carriers in the IGZO channel is significantly suppressed. As a result, the corresponding photoresponsivity at a wavelength of 447 nm can be promoted from 0.05 A W −1 to 0.3 A W −1 . A corresponding maximum external quantum efficiency of 83.4% was obtained for the BN/BP decorated IGZO phototransistor. The results imply that such interface engineering via 2D materials can be used as a general route to high performance oxide-semiconductor based optoelectronic devices.
Publisher: American Chemical Society (ACS)
Date: 29-11-2021
Abstract: pH sensing using active nanomaterials is promising in many fields ranging from chemical reactions to biochemistry, biomedicine, and environmental safety especially in the nanoscale. However, it is still challenging to achieve nanotechnology-enhanced rapid, sensitive, and quantitative pH detection with stable, biocompatible, and cost-effective materials. Here, we report a rational design of nitrogen-doped graphene quantum dot (NGQD)-based pH sensors by boosting the NGQD pH sensing properties via microplasma-enabled band-structure engineering. Effectively and economically, the emission-tunable NGQDs can be synthesized from earth-abundant chitosan biomass precursor by controlling the microplasma chemistry under ambient conditions. Advanced spectroscopy measurements and density functional theory (DFT) calculations reveal that functionality-tuned NGQDs with enriched -OH functional groups and stable and large Stokes shift along the variations of pH value can achieve rapid, label-free, and ionic-stable pH sensing with a wide sensing range from pH 1.8 to 13.6. The underlying mechanism of pH sensing is related to the protonation/deprotonation of -OH group of NGQDs, leading to the maximum pH-dependent luminescence peak shift along with the bandgap broadening or narrowing. In just 1 h, a single microplasma jet can produce a stable colloidal NGQD dispersion with 10 mg/mL concentration lasting for at least 100 pH detections, and the process is scalable. This approach is generic and opens new avenues for nanographene-based materials synthesis for applications in sensing, nanocatalysis, energy generation and conversion, quantum optoelectronics, bioimaging, and drug delivery.
Publisher: Informa UK Limited
Date: 10-2014
Publisher: Elsevier BV
Date: 05-2022
Publisher: Elsevier BV
Date: 12-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9TA00696F
Abstract: Low temperature NH 3 plasma modification of Ni MOF-74 yields a highly efficient hydrogen evolution catalyst with a carambola-like hierarchical 3D structure, which is composed of ultrafine Ni nanocrystals encapsulated in a thin layer of N doped carbon.
Publisher: Informa UK Limited
Date: 08-03-2022
Publisher: Public Library of Science (PLoS)
Date: 27-06-2014
Publisher: Elsevier BV
Date: 06-2018
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2011
Publisher: AIP Publishing
Date: 15-01-2007
DOI: 10.1063/1.2423224
Abstract: Optically transparent, highly oriented nanocrystalline AlN(002) films have been synthesized using a hybrid plasma enhanced chemical vapor deposition and plasma-assisted radio frequency (rf) magnetron sputtering process in reactive Ar+N2 and Ar+N2+H2 gas mixtures at a low Si(111)/glass substrate temperature of 350 °C. The process conditions, such as the sputtering pressure, rf power, substrate temperature, and N2 concentration were optimized to achieve the desired structural, compositional, and optical characteristics. X-ray diffractometry reveals the formation of highly c-oriented AlN films at a sputtering pressure of 0.8 Pa. Field emission scanning electron microscopy suggests the uniform distribution of AlN grains over large surface areas and also the existence of highly oriented in the (002) direction columnar structures of a typical length ∼100−500 nm with an aspect ratio of ∼7−15. X-ray photoelectron and energy dispersive x-ray spectroscopy suggest that films deposited at a rf power of 400 W feature a chemically pure and near stoichiometric AlN. The bonding states of the AlN films have been confirmed by Raman and Fourier transform infrared spectroscopy showing strong E2 (high) and E1 transverse optical phonon modes. Hydrogenated AlN films feature an excellent optical transmittance of ∼80% in the visible region of the spectrum, promising for advanced optical applications.
Publisher: AIP Publishing
Date: 10-2015
DOI: 10.1063/1.4934603
Abstract: The interaction of time-varying electromagnetic fields and solid, liquid, and gaseous matter may lead to electrical breakdown phenomena through the excitation of ionization waves or streamers that control the dynamics of localized plasma propagation through the media. The streamers usually propagate along straight lines, either between random points in space or along a certain direction in a guided mode. Here, we report on a new type of plasma discharges with the regular helical propagation pattern driven by a pulsed dc voltage in nitrogen at sub-atmospheric-pressure conditions. The helical guided streamers, named chiral streamers or chi-streamers, are excited without any external magnetic fields, which commonly cause helical plasma motions. We also demonstrate a hybrid propagation mode involving the interchangeable chiral streamers and the straight-line propagating plasmas. High-speed, time-resolved optical imaging reveals that the chiral streamers and the hybrid patterns are made of spatially localized discrete plasma bullets, similar to the straight-line guided streamers. These results may enable effective control of propagation of confined plasmas and electromagnetic energy along pre-determined, potentially deterministic paths, which have important implications for the development of next-generation plasma-based radiation sources, communication devices, and medical treatments.
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D1NR06411H
Abstract: The electrochemical synthesis of ammonia using nanolayered catalyst of RuO 2 and CeO 2 on a 3D-Graphene support at an ambient condition, demonstrates excellent NRR activity with long-term stability.
Publisher: IOP Publishing
Date: 06-10-2021
Publisher: Wiley
Date: 23-04-2020
Publisher: AIP Publishing
Date: 09-2011
DOI: 10.1063/1.3638131
Publisher: Wiley
Date: 06-08-2021
Abstract: Polyoxometalate (POM) clusters containing lanthanide ion (LnPOM) possess excellent luminescence features, but the envisaged applications are hindered by the challenges in integration into functional architectures. Herein, a novel cross‐linked cyclodextrin (CL‐CD) and LnPOM composite is developed and applied for discriminative detection of inorganic and organic phosphate phases. For inorganic phosphates, a ratiometric fluorescence response is demonstrated with excellent selectivity, and anti‐interference ability in complex analyte mixtures. The outstanding performance is attributed to the high affinity of POM and distinct interactions between La 3+ and Eu 3+ with the phosphate. For organophosphates, a “signal‐off” fluorescence response for p ‐nitrophenyl‐substituted organophosphates is discovered due to the encapsulation of nitrophenyl group into the hydrophobic cavity of CD that enhances the interactions between POM and p ‐nitrophenyl phosphate. The discriminative responses of CL‐CD–LnPOM to inorganic phosphates and organophosphates bring new insights into POM‐based fluorescence probes for the detection of inorganic and organic phases based on the intrinsic structural difference between the phosphate analogs.
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3TA03100D
Abstract: A novel electrolyte with a strong–weak binary solvation structure is proposed to balance the conductivity and desolvation energy. The supercapacitors based on this new electrolyte realize outstanding energy and power densities even at −70 °C.
Publisher: Elsevier BV
Date: 11-2021
Publisher: Wiley
Date: 16-04-2020
Publisher: Elsevier BV
Date: 2019
Publisher: Wiley
Date: 02-02-2023
Abstract: One of the major challenges on the way to low‐cost, simple, and effective cancer treatments is the lack of smart anticancer drug delivery materials with the requisite of site‐specific and microenvironment‐responsive properties. This work reports the development of plasma‐engineered smart drug nanocarriers (SDNCs) containing chitosan and nitrogen‐doped graphene quantum dots (NGQDs) for drug delivery in a pH‐responsive manner. Through a customized microplasma processing, a highly cross‐linked SDNC with only 4.5% of NGQD ratio can exhibit enhanced toughness up to threefold higher than the control chitosan group, avoiding the commonly used high temperatures and toxic chemical cross‐linking agents. The SDNCs demonstrate improved loading capability for doxorubicin (DOX) via π–π interactions and stable solid‐state photoluminescence to monitor the DOX loading and release through the Förster resonance energy transfer (FRET) mechanism. Moreover, the DOX loaded SDNC exhibits anticancer effects against cancer cells during cytotoxicity tests at minimum concentration. Cellular uptake studies confirm that the DOX loaded SDNC can be successfully internalized into the nucleus after 12 h incubation period. This work provides new insights into the development of smart, environmental‐friendly, and biocompatible nanographene hydrogels for the next‐generation biomedical applications.
Publisher: Wiley
Date: 04-09-2021
Publisher: The Optical Society
Date: 17-08-2011
DOI: 10.1364/OE.19.017167
Publisher: Wiley
Date: 10-08-2007
Publisher: IOP Publishing
Date: 04-2013
Publisher: AIP Publishing
Date: 04-2010
DOI: 10.1063/1.3381132
Abstract: Cold atmospheric-pressure plasma plumes are generated in the ambient air by a single-electrode plasma jet device powered by pulsed dc and ac sine-wave excitation sources. Comprehensive comparisons of the plasma characteristics, including electrical properties, optical emission spectra, gas temperatures, plasma dynamics, and bacterial inactivation ability of the two plasmas are carried out. It is shown that the dc pulse excited plasma features a much larger discharge current and stronger optical emission than the sine-wave excited plasma. The gas temperature in the former discharge remains very close to the room temperature across the entire plume length the sine-wave driven discharge also shows a uniform temperature profile, which is 20–30 degrees higher than the room temperature. The dc pulse excited plasma also shows a better performance in the inactivation of gram-positive staphylococcus aureus bacteria. These results suggest that the pulsed dc electric field is more effective for the generation of nonequilibrium atmospheric pressure plasma plumes for advanced plasma health care applications.
Publisher: American Chemical Society (ACS)
Date: 09-11-2020
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2013
Publisher: Elsevier BV
Date: 05-2015
Publisher: American Chemical Society (ACS)
Date: 23-12-2022
Publisher: IOP Publishing
Date: 06-05-2009
DOI: 10.1088/0957-4484/20/21/215606
Abstract: Silicon thin films with a variable content of nanocrystalline phase were deposited on single-crystal silicon and glass substrates by inductively coupled plasma-assisted chemical vapor deposition using a silane precursor without any hydrogen dilution in the low substrate temperature range from 100 to 300 degrees C. The structural and optical properties of the deposited films are systematically investigated by Raman spectroscopy, x-ray diffraction, Fourier transform infrared absorption spectroscopy, UV/vis spectroscopy, scanning electron microscopy and high-resolution transmission electron microscopy. It is shown that the structure of the silicon thin films evolves from the purely amorphous phase to the nanocrystalline phase when the substrate temperature is increased from 100 to 150 degrees C. It is found that the variations of the crystalline fraction f(c), bonded hydrogen content C(H), optical bandgap E(Tauc), film microstructure and growth rate R(d) are closely related to the substrate temperature. In particular, at a substrate temperature of 300 degrees C, the nanocrystalline Si thin films of our interest feature a high growth rate of 1.63 nm s(-1), a low hydrogen content of 4.0 at.%, a high crystalline fraction of 69.1%, a low optical bandgap of 1.55 eV and an almost vertically aligned columnar structure with a mean grain size of approximately 10 nm. It is also shown that the low-temperature synthesis of nanocrystalline Si thin films without any hydrogen dilution is attributed to the outstanding dissociation ability of the high-density inductively coupled plasmas and effective plasma-surface interactions during the growth process. Our results offer a highly effective yet simple and environmentally friendly technique to synthesize high-quality nanocrystalline Si films, vitally needed for the development of new-generation solar cells and other emerging nanotechnologies.
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3TC30750F
Publisher: IOP Publishing
Date: 13-06-2022
Abstract: Plasma catalysis is an emerging process electrification technology for industry decarbonization. Plasma-catalytic dry reforming of methane relies on the mutual effects of the plasma and the catalyst leading to the higher chemical conversion efficiency. The effects of catalyst surfaces on the plasma are predicted to play a major role, yet they remain unexplored. Here, a 1D plasma fluid model combined with 0D surface kinetics is developed to reveal how the surface reactions on platinum (Pt) catalyst affect the redistribution of the gas-phase particles. Two contrasting models with and without the surface kinetics as well as the Spearman rank correlation coefficients are used to quantify the effect of the key species (H, CH, CH 2 ) on the CO generation. Advancing the common knowledge that Pt catalyst can influence the plasma chemistry directly by changing the surface loss roduction of particles, this study reveals that the catalyst can also affect the spatial distributions of active species, thereby influencing the plasma chemistry in an indirect way. This result goes beyond the existing state-of-the-art which commonly relies on over-simplified 0D models which cannot resolve the spatial distribution. Further analysis indicates that the species spatial redistribution is driven by the dynamic catalyst surface adsorption-desorption processes. This work enables the previously elusive account of active species redistribution and may open new opportunities for plasma-catalytic sustainable chemical processes.
Publisher: Elsevier BV
Date: 11-2021
Publisher: Elsevier BV
Date: 08-2021
Publisher: AIP Publishing
Date: 26-05-2005
DOI: 10.1063/1.1925547
Abstract: A generic approach towards tailoring of ion species composition in reactive plasmas used for nanofabrication of various functional nanofilms and nanoassemblies, based on a simplified model of a parallel-plate rf discharge, is proposed. The model includes an idealized reactive plasma containing two neutral and two ionic species interacting via charge exchange collisions in the presence of a microdispersed solid component. It is shown that the number densities of the desired ionic species can be efficiently managed by adjusting the dilution of the working gas in a buffer gas, rates of electron impact ionization, losses of plasma species on the discharge walls, and surfaces of fine particles, charge exchange rates, and efficiency of three-body recombination processes in the plasma bulk. The results are relevant to the plasma-aided nanomanufacturing of ordered patterns of carbon nanotip and nanopyramid microemitters.
Publisher: Elsevier BV
Date: 11-2021
Publisher: Elsevier BV
Date: 09-2020
Publisher: Elsevier BV
Date: 10-2019
Publisher: Springer Science and Business Media LLC
Date: 10-1995
DOI: 10.1007/BF01540120
Publisher: AIP Publishing
Date: 09-2014
DOI: 10.1063/1.4895496
Abstract: The production mechanism of OH radicals in a pulsed DC plasma jet is studied by a two-dimensional (2-D) plasma jet model and a one-dimensional (1-D) discharge model. For the plasma jet in the open air, electron-impact dissociation of H2O, electron neutralization of H2O+, as well as dissociation of H2O by O(1D) are found to be the main reactions to generate the OH species. The contribution of the dissociation of H2O by electron is more than the others. The additions of N2, O2, air, and H2O into the working gas increase the OH density outside the tube slightly, which is attributed to more electrons produced by Penning ionization. On the other hand, the additions of O2 and H2O into the working gas increase the OH density inside the tube substantially, which is attributed to the increased O (1D) and H2O concentration, respectively. The gas flow will transport high density OH out of the tube during pulse off period. It is also shown that the plasma chemistry and reactivity can be effectively controlled by the pulse numbers. These results are supported by the laser induced fluorescence measurements and are relevant to several applications of atmospheric-pressure plasmas in health care, medicine, and materials processing.
Publisher: Springer Science and Business Media LLC
Date: 12-08-2014
Abstract: Control over nucleation and growth of multi-walled carbon nanotubes in the nanochannels of porous alumina membranes by several combinations of posttreatments, namely exposing the membrane top surface to atmospheric plasma jet and application of standard S1813 photoresist as an additional carbon precursor, is demonstrated. The nanotubes grown after plasma treatment nucleated inside the channels and did not form fibrous mats on the surface. Thus, the nanotube growth mode can be controlled by surface treatment and application of additional precursor, and complex nanotube-based structures can be produced for various applications. A plausible mechanism of nanotube nucleation and growth in the channels is proposed, based on the estimated depth of ion flux penetration into the channels. PACS 63.22.Np Layered systems 68. Surfaces and interfaces Thin films and nanosystems (structure and non-electronic properties) 81.07.-b Nanoscale materials and structures: fabrication and characterization
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7RA00478H
Abstract: Physical and chemical mechanisms and role of plasma in the synthesis of hydrogenated amorphous silicon were studied numerically to reveal the key growth processes and, hence, to ensure a higher level of control over the film structure and properties.
Publisher: Wiley
Date: 11-02-2015
Publisher: American Chemical Society (ACS)
Date: 13-07-2016
Abstract: Carbon nanotube (CNT) growth has been demonstrated recently using a number of nonmetallic semiconducting and metal oxide nanoparticles, opening up pathways for direct CNT synthesis from a number of more desirable templates without the need for metallic catalysts. However, CNT growth mechanisms using these nonconventional catalysts has been shown to largely differ and reamins a challenging synthesis route. In this contribution we show CNT growth from partially oxidized silicon nanocrystals (Si NCs) that exhibit quantum confinement effects using a microwave plasma enhanced chemical vapor deposition (PECVD) method. On the basis of solvent and a postsynthesis frgamentation process, we show that oxidation of our Si NCs can be easily controlled. We determine experimentally and explain with theoretical simulations that the Si NCs morphology together with a necessary shell oxide of ∼1 nm is vital to allow for the nonmetallic growth of CNTs. On the basis of chemical analysis post-CNT-growth, we give insight into possible mechanisms for CNT nucleation and growth from our partially oxidized Si NCs. This contribution is of significant importance to the improvement of nonmetallic catalysts for CNT growth and the development of Si NC/CNT interfaces.
Publisher: No publisher found
Date: 2019
Publisher: Springer Science and Business Media LLC
Date: 03-05-2016
Publisher: American Chemical Society (ACS)
Date: 10-2019
Abstract: Elemental alloying in monolayer, two-dimensional (2D) transition metal dichalcogenides (TMDs) promises unprecedented ability to modulate their electronic structure leading to unique optoelectronic properties. MoS
Publisher: Cold Spring Harbor Laboratory
Date: 02-06-2023
DOI: 10.1101/2023.05.30.542966
Abstract: Cold atmospheric plasma (CAP) holds promise as a cancer-specific treatment that selectively kills basal-like breast cancer cells. We used CAP-activated media (PAM) to capture the multi-modal chemical species of CAP. Specific antibodies, small molecule inhibitors and CRISPR/Cas9 gene-editing approaches showed an essential role for receptor tyrosine kinases, especially epidermal growth factor (EGF) receptor, in mediating triple negative breast cancer (TNBC) cell responses to PAM. EGF also dramatically enhanced the sensitivity and specificity of PAM against TNBC cells. Site-specific phospho-EGFR analysis, signal transduction inhibitors and reconstitution of EGFR-depleted cells with EGFR-mutants confirmed the role of phospho-tyrosines 992/1173 and phospholipase C gamma signaling in upregulating levels of reactive oxygen species above the apoptotic threshold. EGF-triggered EGFR activation enhanced the sensitivity and selectivity of PAM effects on TNBC cells, such that a strategy based on the synergism of CAP and EGF therapy may provide new opportunities to improve the clinical management of TNBC.
Publisher: Elsevier BV
Date: 10-2018
Publisher: American Vacuum Society
Date: 03-10-2018
DOI: 10.1116/1.5030718
Abstract: Recently developed atmospheric pressure plasma jet (APPJ) is considered as a novel and efficient technique for uneven surfaces processing and APPJ array effectively expands the treatment area of a single APPJ. In this paper, a two-dimensional (2D) APPJ array in Ar/tetramethylsilane (TMS) is used to improve the surface hydrophobicity of polymethyl methacrylate (PMMA) by depositing polymerized silicalike clusters on the jet-PMMA interface. The electrical and optical characteristics of the 2D Ar/TMS APPJ array are measured to optimize experimental conditions. The wettability of jet-PMMA interface is assessed by measuring water contact angle, which increases from 65° to a maximum value of 115° after 240 s plasma treatment at 0.04% TMS content. Scanning electron microscopy is used to investigate the micro- and nanoscale surface morphology of PMMA after plasma treatment, and it is found that there are clusters of particles with diameters of hundreds of nanometers attached on the PMMA surface. The changes of the chemical composition and chemical bonding on the PMMA surface are further analyzed using Fourier transform infrared and x-ray photoelectron spectroscopies. It is found that the silicon-containing groups, such as Si-CH3, Si-H, and Si-O-Si, replace oxygen-containing hydrophilic polar groups (C—O and C=O), reduce the surface polarity, decrease the surface tension, and increase the surface hydrophobicity. For the intensive peak of Si-O-Si in FTIR spectra, the improvement of hydrophobicity of the PMMA surface is caused by the hydrophobic polymerized Si-O-Si thin film. The results demonstrate that the APPJ array as a novel atmospheric pressure plasma device provides an efficient way to modify large uneven material surfaces.
Publisher: Elsevier BV
Date: 04-2001
Publisher: Copernicus GmbH
Date: 16-10-2020
DOI: 10.5194/ACP-20-11717-2020
Abstract: Abstract. Artificial rain is explored as a remedy for climate change caused farmland drought and bushfires. Increasing the ion density in the open air is an efficient way to generate charged nuclei from atmospheric aerosols and induce precipitation or eliminate fog. Here we report on the development of a large commercial-installation-scale atmospheric ion generator based on corona plasma discharges, experimental monitoring, and numerical modeling of the parameters and range of the atmospheric ions, as well as the application of the generated ions to produce charged aerosols and induce precipitation at the scale of a large cloud chamber. The coverage area of the ions generated by the large corona discharge installation with the 7.2 km long wire electrode and applied voltage of −90 kV is studied under prevailing weather conditions including wind direction and speed. By synergizing over 300 000 localized corona discharge points, we demonstrate a substantial decrease in the decay of ions compared to a single corona discharge point in the open air, leading to large-scale (30 m ×23 m ×90 m) ion coverage. Once aerosols combine with the generated ions, charged nuclei are produced. Higher wind speed has led to larger areas covered by the plasma-generated ions. The cloud chamber experiments (relative humidity 130±10 %) suggest that charged aerosols generated by ions with a density of ∼104 cm−3 can accelerate the settlement of moisture by 38 %. These results are promising for the development of large-scale installations for the effective localized control of atmospheric phenomena.
Publisher: Wiley
Date: 22-05-2013
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C1JM10318K
Publisher: American Chemical Society (ACS)
Date: 16-02-2017
Abstract: Nanotextured surfaces (NTSs) are critical to organisms as self-adaptation and survival tools. These NTSs have been actively mimicked in the process of developing bactericidal surfaces for erse biomedical and hygiene applications. To design and fabricate bactericidal topographies effectively for various applications, understanding the bactericidal mechanism of NTS in nature is essential. The current mechanistic explanations on natural bactericidal activity of nanopillars have not utilized recent advances in microscopy to study the natural interaction. This research reveals the natural bactericidal interaction between E. coli and a dragonfly wing's (Orthetrum villosovittatum) NTS using advanced microscopy techniques and proposes a model. Contrary to the existing mechanistic models, this experimental approach demonstrated that the NTS of Orthetrum villosovittatum dragonfly wings has two prominent nanopillar populations and the resolved interface shows membrane damage occurred without direct contact of the bacterial cell membrane with the nanopillars. We propose that the bacterial membrane damage is initiated by a combination of strong adhesion between nanopillars and bacterium EPS layer as well as shear force when immobilized bacterium attempts to move on the NTS. These findings could help guide the design of novel biomimetic nanomaterials by maximizing the synergies between biochemical and mechanical bactericidal effects.
Publisher: Wiley
Date: 10-03-2022
Abstract: Anatase TiO 2 is a promising anode material for lithium‐ion batteries (LIBs) and sodium‐ion batteries (SIBs) due to its high specific capacity, low cost, and excellent cycle stability. However, low electrical conductivity and poor Na + ion transport in TiO 2 limit its practical applications. Here, substantially boosted Na + ion transport and charge transfer kinetics are demonstrated by constructing a near‐ideal non‐rectifying titanium carbonitride/nitrogen‐doped TiO 2 (TiC x N 1– x /N‐TiO 2 ) heterostructure. Owing to the fast plasma effects and metastable hybrid phases, the TiC x N 1– x is epitaxially grown on TiO 2 . Energy band engineering at the interface induces high electron densities and a strong built‐in electric field, which lowers the Na + diffusion barrier by a factor of 1.7. As a result, the TiC x N 1– x /N‐TiO 2 electrode exhibits excellent electrochemical performance. The reversible specific capacities at rates of 0.1 and 10 C reach 312.3 and 173.7 mAh g −1 , respectively. After 600 cycles of charge and discharge at 10 C, the capacity retention rate is 98.7%. This work discovers an effective non‐equilibrium plasma‐enabled process to construct heterointerfaces that can enhance Na + ion transport and provides generic guidelines for the design of heterostructures for a broader range of energy storage, separation, and other devices that rely on controlled ionic transport.
Publisher: American Chemical Society (ACS)
Date: 23-03-2012
DOI: 10.1021/JA300805S
Abstract: Precisely controlled reactive chemical vapor synthesis of highly uniform, dense arrays of vertically aligned single-walled carbon nanotubes (SWCNTs) using tailored trilayered Fe/Al(2)O(3)/SiO(2) catalyst is demonstrated. More than 90% population of thick nanotubes (>3 nm in diameter) can be produced by tailoring the thickness and microstructure of the secondary catalyst supporting SiO(2) layer, which is commonly overlooked. The proposed model based on the atomic force microanalysis suggests that this tailoring leads to uniform and dense arrays of relatively large Fe catalyst nanoparticles on which the thick SWCNTs nucleate, while small nanotubes and amorphous carbon are effectively etched away. Our results resolve a persistent issue of selective (while avoiding multiwalled nanotubes and other carbon nanostructures) synthesis of thick vertically aligned SWCNTs whose easily switchable thickness-dependent electronic properties enable advanced applications in nanoelectronic, energy, drug delivery, and membrane technologies.
Publisher: Wiley
Date: 28-11-2007
DOI: 10.1002/JBM.A.30987
Abstract: This contribution sheds light on the role of crystal size and phase composition in inducing biomimetic apatite growth on the surface of nanostructured titania films synthesized by reactive magnetron sputtering of Ti targets in Ar+O(2) plasmas. Unlike most existing techniques, this method enables one to deposit highly crystalline titania films with a wide range of phase composition and nanocrystal size, without any substrate heating or postannealing. Moreover, by using this dry plasma-based method one can avoid surface hydroxylation at the deposition stage, almost inevitable in wet chemical processes. Results of this work show that high phase purity and optimum crystal size appear to be the essential requirement for efficient apatite formation on magnetron plasma-fabricated bioactive titania coatings.
Publisher: Wiley
Date: 05-06-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D2NH00447J
Abstract: We focus on the new horizons in operando / in situ characterisation techniques in electrocatalysis, providing a critical analysis of how advanced in situ techniques help us to deepen our understanding of reaction mechanisms and material evolution.
Publisher: Hindawi Limited
Date: 2015
DOI: 10.1155/2015/230987
Abstract: Vertical graphene nanosheets have advantages over their horizontal counterparts, primarily due to the larger surface area available in the vertical systems. Vertical sheets can accommodate more functional particles, and, due to the conduction and optical properties of thin graphene, these structures can find niche applications in the development of sensing and energy storage devices. This work is a combined experimental and theoretical study that reports on the synthesis and optical responses of vertical sheets decorated with gold nanoparticles. The findings help in interpreting optical responses of these hybrid graphene structures and are relevant to the development of future sensing platforms.
Publisher: American Chemical Society (ACS)
Date: 16-09-2011
DOI: 10.1021/NN2030989
Abstract: Multiscale, multiphase numerical modeling is used to explain the mechanisms of effective control of chirality distributions of single-walled carbon nanotubes in direct plasma growth and suggest effective approaches to further improvement. The model includes an unprecedented combination of the plasma sheath, ion/radical transport, species creation/loss, plasma-surface interaction, heat transfer, surface/bulk diffusion, graphene layer nucleation, and bending/lift-off modules. It is shown that the constructive interplay between the plasma and the Gibbs-Thomson effect can lead to the effective nucleation and lift-off of small graphene layers on small metal catalyst nanoparticles. As a result, much thinner nanotubes with narrower chirality distributions can nucleate at much lower process temperatures and pressures compared to thermal CVD. This approach is validated by a host of experimental results, substantially reduces the amounts of energy and atomic matter required for the nanotube growth, and can be extended to other nanoscale structures and materials systems, thereby nearing the ultimate goal of energy- and matter-efficient nanotechnology.
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7RA11628D
Abstract: Functionalized graphene can successfully anchor sulfur compounds via moderate interactions, leading to improved conductivity and charge transfer in the cathode of Li–S batteries.
Publisher: MDPI AG
Date: 19-06-2021
DOI: 10.3390/MI12060719
Abstract: The environmental crisis, due to the rapid growth of the world population and globalisation, is a serious concern of this century. Nanoscience and nanotechnology play an important role in addressing a wide range of environmental issues with innovative and successful solutions. Identification and control of emerging chemical contaminants have received substantial interest in recent years. As a result, there is a need for reliable and rapid analytical tools capable of performing s le analysis with high sensitivity, broad selectivity, desired stability, and minimal s le handling for the detection, degradation, and removal of hazardous contaminants. In this review, various gold–carbon nanocomposites-based sensors/biosensors that have been developed thus far are explored. The electrochemical platforms, synthesis, erse applications, and effective monitoring of environmental pollutants are investigated comparatively.
Publisher: Elsevier BV
Date: 07-2021
Publisher: Elsevier BV
Date: 07-2022
Publisher: American Vacuum Society
Date: 27-01-2014
DOI: 10.1116/1.4862093
Abstract: Metal-insulator-metal (MIM) capacitors with lanthanum oxide (La2O3) high-κ dielectric, for potential applications in mixed-signal integrated circuit (IC), have been fabricated using a dense plasma focus device. The electrical characteristics and morphological properties of the fabricated nanodevices are studied. The MIM capacitors were further annealed to enhance the electrical properties in terms of the low leakage current density, the high capacitance density, and the improved capacitance voltage linearity. The minimum leakage current densities of ∼1.6 × 10−9 A/cm2 and ∼2.0 × 10−10 A/cm2 at −1 V are obtained along with the maximum capacitance densities of ∼17.96 fF/μm2 at 100 kHz and ∼19.10 fF/μm2 at 1 MHz, 0 V for as-fabricated and annealed MIM capacitors having 15 nm thick dielectric layers as measured using ellipsometry. The nanofilms with the minimum root mean square roughness of ∼10 nm are examined using atomic force microscopy. The results are superior compared to some other MIM capacitors and can be optimized to achieve the best electrical parameters for potential applications in radio frequency (RF)/mixed signal ICs. The high frequency C-V measurements indicate an increase in the capacitance density upon increasing the frequency which supports the possibility of potential high-frequency/RF applications of the MIM capacitors.
Publisher: AIP Publishing
Date: 22-11-2010
DOI: 10.1063/1.3517507
Abstract: Synthesis of one-dimensional AlN nanostructures commonly requires high process temperatures (& °C), metal catalyst, and hazardous gas owder precursors. We report on a simple, single-step, catalyst-free, plasma-assisted growth of dense patterns of size-uniform single-crystalline AlN nanorods at a low substrate temperature (∼650 °C) without any catalyst or hazardous precursors. This unusual growth mechanism is based on highly effective plasma dissociation of N2 molecules, localized species precipitation on AlN islands, and reduced diffusion on the nitrogen-rich surface. This approach can also be used to produce other high-aspect-ratio oxide and nitride nanostructures for applications in energy conversion, sensing, and optoelectronics.
Publisher: Elsevier BV
Date: 2009
Publisher: Wiley
Date: 09-07-2020
Publisher: Wiley
Date: 30-11-2021
DOI: 10.1002/APP.51980
Abstract: A simple and economic atmospheric plasma spraying method for thermal barrier coatings (TBCs) preparation on the mold cavity was developed to improve the injection parts properties. 7 wt% yttria stabilized zirconia was used as spray material with polyamide 11 (PA 11) as pore‐forming agents to improve the coating properties. The effect of PA 11 powder contents on the microstructure, thermal conductivity, bonding strength and hardness of TBCs were studied. The results show that the thermal conductivity of TBCs decreased with the addition of PA 11, and the bonding strength reached maximum of 21.38 MPa with 10% PA 11 addition. Further studies confirm that TBCs were able to maintain a high and stable temperature in the mold cavity due to its low thermal conductivity, validated by the elimination of the welding line. With TBCs, the average tensile strength and elongation at yield of the injection parts increased by 25.6% and 128%, respectively.
Publisher: Springer Science and Business Media LLC
Date: 09-2016
DOI: 10.1038/SREP32603
Abstract: Atmospheric-pressure N 2 , He, air, and O 2 microplasma arrays have been used to investigate the effects of plasma treatment on seed germination and seedling growth of mung bean in aqueous solution. Seed germination and growth of mung bean were found to strongly depend on the feed gases used to generate plasma and plasma treatment time. Compared to the treatment with atmospheric-pressure O 2 , N 2 and He microplasma arrays, treatment with air microplasma arrays was shown to be more efficient in improving both the seed germination rate and seedling growth, the effect attributed to solution acidification and interactions with plasma-generated reactive oxygen and nitrogen species. Acidic environment caused by air discharge in water may promote leathering of seed chaps, thus enhancing the germination rate of mung bean, and stimulating the growth of hypocotyl and radicle. The interactions between plasma-generated reactive species, such as hydrogen peroxide (H 2 O 2 ) and nitrogen compounds, and seeds led to a significant acceleration of seed germination and an increase in seedling length of mung bean. Electrolyte leakage rate of mung bean seeds soaked in solution activated using air microplasma was the lowest, while the catalase activity of thus-treated mung bean seeds was the highest compared to other types of microplasma.
Publisher: Wiley
Date: 23-03-0006
Publisher: Elsevier BV
Date: 03-2019
DOI: 10.1016/J.JCIS.2018.11.025
Abstract: Capacitive deionization (CDI) has become a promising technology for water desalination due to its remarkable advantages including low operation cost, no secondary pollution and high rate of ion recovery. However, the majority of commercial CDI electrode materials are carbonaceous materials such as activated carbon with limited capacitance and high charge transfer resistance, which significantly hinders the wide application of CDI. Herein, we demonstrate a N-doped carbonaceous CDI electrode with a maximum ion electrosorption capacity of 19.9 mg/g, a low charge transfer resistance (1.17 Ω) and a robust regeneration performance (2800 min for 28 circles). The N-doped carbonaceous CDI electrode is the commercial activated carbon fiber (ACF) decorated with polyaniline (PANI) (ACF/PANI) electrode fabricated by in-situ electrochemical polymerization. The ACF/PANI electrode was characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), and fourier transform infrared spectroscopy (FTIR), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The pseudocapacitance of ACF/PANI electrode significantly contributed to the effectively improved CDI performance that 90.0% of sodium storage was attributed to the capacitive process and the unique porous structure of ACF/PANI electrode contributed to the other 10.0% diffusion-controlled capacity.
Publisher: Wiley
Date: 13-10-2022
Abstract: The halide perovskite nanocrystals (P‐NCs) can address a plethora of issues of the light‐emission technologies, due to its low temperature processing. To successfully employ P‐NCs for light‐emitting diodes (LEDs), one needs to resolve the issues of stability of the LEDs. The stability of device can be achieved by charge balance of electrons and holes recombination in active material. To investigate this herein, a self‐assembled carbon dots (CDs) layer is fabricated from waste small strands of human hair. The self‐assembled CDs layer is used beneath P‐NCs layer to reduce the band‐off set for hole transport, thus balancing the electron and holes carrier in active layer. The layer is used as an active light‐emitting layer to fabricate a LED device that exhibits green luminescence of 4800 cd m −2 at a current efficiency of 10.7 cd A −1 and external quantum efficiency of 4.8%. The LED exhibits operational stability of nearly 200 h. The same film is used to demonstrate a flexible device with maximum luminescence of 2259 cd m −2 , with a high current density of 474 mA cm −2 , current efficiency of 1.37 cd A −1 and a low turn‐on voltage of 3.5 V. All the display devices are measured in air without encapsulation.
Publisher: Elsevier BV
Date: 11-2020
Publisher: Wiley
Date: 13-12-2019
Publisher: Wiley
Date: 26-07-2022
Abstract: Carbon quantum dots (CQDs, C‐dots or CDs) are an emerging type of nanomaterial which has received immense attention due to their numerous applications. However, most of the reported CQDs in literature typically emit single emission peak under an excitation. Multipeak emissions without any complicated techniques will be ideal for various applications in the fields of ratiometric sensing, optoelectronics, and multifunctional bio‐imaging systems. Here, a fast, effective, and single‐step method is developed for the bulk synthesis of CQDs using atmospheric pressure air plasmas. Structural, morphological, and chemical properties are characterized by advanced analytical techniques. The CQDs have an average diameter of about 3 nm with a narrow size distribution. Emission wavelengths of 470 nm for blue emissive CQDs and 515 nm for green emissive CQDs are observed. Concentration dependency of the CQDs suggests that the switchable mechanism is due to the formation of PTSA excimers. Dual‐emissive CQDs have the potential to be used in bi‐channel ratiometric determination for metal ions, pH sensing, tumor diagnosis and detection, and solid‐state lighting materials. The proof‐of‐principle demonstration of the use of dual‐emissive CQDs (DCQDs) as a fluorescent sensor of Cu 2+ ions is also presented to highlight the possible applications.
Publisher: AIP Publishing
Date: 17-07-2006
DOI: 10.1063/1.2222249
Abstract: It is shown that, owing to selective delivery of ionic and neutral building blocks directly from the ionized gas phase and via surface migration, plasma environments offer a better deal of deterministic synthesis of ordered nanoassemblies compared to thermal chemical vapor deposition. The results of hybrid Monte Carlo (gas phase) and adatom self-organization (surface) simulation suggest that higher aspect ratios and better size and pattern uniformity of carbon nanotip microemitters can be achieved via the plasma route.
Publisher: Wiley
Date: 08-11-2019
Publisher: Elsevier BV
Date: 2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5NR00250H
Abstract: An electrostatic model is developed to qualitatively explain the protein adsorption based on charge-induced pH modifications near the charged nanoparticles/surfaces.
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8RA08890J
Abstract: Bottom-gate-top-contact OFET device structure using PBIBDF-TVT and PBIBDF-TBT based polymer semiconductors.
Publisher: AIP Publishing
Date: 12-2010
DOI: 10.1063/1.3526678
Abstract: Highly effective (more than 99.9%) inactivation of a pathogenic fungus Candida albicans commonly found in oral, respiratory, digestive, and reproduction systems of a human body using atmospheric-pressure plasma jets sustained in He+O2 gas mixtures is reported. The inactivation is demonstrated in two fungal culture configurations with open (Petri dish without a cover) and restricted access to the atmosphere (Petri dish with a cover) under specific experimental conditions. It is shown that the fungal inactivation is remarkably more effective in the second configuration. This observation is supported by the scanning and transmission electron microscopy of the fungi before and after the plasma treatment. The inactivation mechanism explains the experimental observations under different experimental conditions and is consistent with the reports by other authors. The results are promising for the development of advanced health care applications.
Publisher: Elsevier BV
Date: 05-2019
Publisher: Elsevier BV
Date: 09-2015
Location: Ukraine
Start Date: 2006
End Date: 2009
Funder: Australian Research Council
View Funded ActivityStart Date: 2006
End Date: 2006
Funder: Australian Research Council
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End Date: 2009
Funder: Australian Research Council
View Funded ActivityStart Date: 2010
End Date: 2014
Funder: Australian Research Council
View Funded ActivityStart Date: 2006
End Date: 2006
Funder: Australian Research Council
View Funded ActivityStart Date: 2010
End Date: 2014
Funder: Australian Research Council
View Funded ActivityStart Date: 2006
End Date: 2006
Funder: Australian Research Council
View Funded ActivityStart Date: 2016
End Date: 2018
Funder: Australian Research Council
View Funded ActivityStart Date: 2018
End Date: 2018
Funder: Australian Research Council
View Funded ActivityStart Date: 2018
End Date: 2018
Funder: Australian Research Council
View Funded ActivityStart Date: 2007
End Date: 2009
Funder: Australian Research Council
View Funded ActivityStart Date: 2006
End Date: 2009
Funder: Australian Research Council
View Funded ActivityStart Date: 2018
End Date: 2020
Funder: Australian Research Council
View Funded ActivityStart Date: 2018
End Date: 2020
Funder: Australian Research Council
View Funded ActivityStart Date: 2016
End Date: 2019
Funder: Australian Research Council
View Funded ActivityStart Date: 2006
End Date: 2006
Funder: Australian Research Council
View Funded ActivityStart Date: 2018
End Date: 2018
Funder: Australian Research Council
View Funded ActivityStart Date: 2018
End Date: 2018
Funder: Australian Research Council
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