ORCID Profile
0000-0003-1460-4983
Current Organisation
University of South Australia
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Publisher: Elsevier
Date: 2017
Publisher: American Chemical Society (ACS)
Date: 20-10-2009
DOI: 10.1021/AM900574M
Abstract: Rod and sphere-like CeO(2) particles were obtained via a supercritical solvothermal method using CeCl(3).7H(2)O and Ce(NO(3))(3).6H(2)O as cerium sources in ethanol and methanol at 400 degrees C for 15 min followed by calcination in air. The rodlike particles were 200-400 nm in diameter and 1-2 mum in length. The spherical particles were 300-500 nm in diameter. The as-prepared rodlike particles using CeCl(3).7H(2)O consisted of mixtures of Ce(OH)(3) and Ce(CH(3)COO)(3) and were converted to rodlike CeO(2) by calcination in air at 500 degrees C. In contrast, the spherical particles prepared using Ce(NO(3))(3).6H(2)O consisted of fluorite-structured CeO(2). The possible formation mechanism was discussed on the basis of the effect of reaction time on the morphology at 400 degrees C. The rod- and spherelike CeO(2) particles exhibited strong UV absorption below 400 nm, and the absorbance edges extend to nearly 500 nm. The rod- and spherelike CeO(2) particles exhibited near-UV emission at 360 nm and blue emission at 465 nm with higher emission intensity compared to the commercial CeO(2) s le.
Publisher: Wiley
Date: 03-2012
Publisher: Springer Science and Business Media LLC
Date: 19-06-2015
DOI: 10.1038/SREP11041
Abstract: Structural studies of high voltage cathode materials are necessary to understand their chemistry to improve the electrochemical performance for applications in lithium ion batteries. LiNiPO 4 nanorods and nanoplates are synthesized via a one pot synthesis using supercritical fluid process at 450 o C for 10 min. The X-ray diffraction (XRD) analysis confirmed that LiNiPO 4 phase is well crystallized, phase purity supported by energy dispersive spectroscopy (EDS) and elemental mapping by scanning electron transmission electron microscopy (STEM). For the first time, we have carried out direct visualization of atom-by-atom structural observation of LiNiPO 4 nanomaterials using high-angle annular dark-field (HAADF) and annular bright-field (ABF) scanning transmission electron microscopy (STEM) analysis. The Rietveld refinement analysis was performed to find out the percentage of antisite defects presents in LiNiPO 4 nanoplates and about 11% of antisite defects were found. Here, we provide the direct evidence for the presence of Ni atoms in Li sites and Li in Ni sites as an antisite defects are provided for understanding of electrochemical behavior of high voltage Li ion battery cathode materials.
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4RA10689J
Abstract: Antisite defects in cathode materials are important to understand the chemistry of cathode materials. Herein, we investigated the antisite defects in LiCoPO 4 nanocrystals synthesized via a supercritical fluid process.
Publisher: Elsevier BV
Date: 10-2013
Publisher: Springer Science and Business Media LLC
Date: 06-12-2007
Publisher: Elsevier BV
Date: 08-2009
Publisher: American Chemical Society (ACS)
Date: 09-10-2013
DOI: 10.1021/AM403018N
Abstract: LiCoPO4 cathode materials have been synthesized by a sol-gel route. X-ray diffraction analysis confirmed that LiCoPO4 was well-crystallized in an orthorhombic structure in the Pmna space group. From the high-resolution transmission electron microscopy (HR-TEM) image, the lattice fringes of {001} and {100} are well-resolved. The HR-TEM image and selected area electron diffraction pattern reveal the highly crystalline nature of LiCoPO4 having an ordered olivine structure. The atom-by-atom structure of LiCoPO4 olivine has been observed, for the first time, using high-angle annular dark-field (HAADF) and annual bright-field scanning transmission electron microscopy. We observed the bright contrast in Li columns in the HAADF images and strong contrast in the ABF images, directly indicating the antisite exchange defects in which Co atoms partly occupy the Li sites. The LiCoPO4 cathode materials delivered an initial discharge capacity of 117 mAh/g at a C/10 rate with moderate cyclic performance. The discharge profile of LiCoPO4 shows a plateau at 4.75 V, revealing its importance as a potentially high-voltage cathode. The direct visualization of atom-by-atom structure in this work represents important information for the understanding of the structure of the active cathode materials for Li-ion batteries.
Publisher: Wiley
Date: 10-2009
Abstract: Tm 3+ ‐doped Y 2 O 3 nanocrystals were prepared via hydrothermal conditions at high autogenous pressure (ca. 40 MPa) using batch reactors at 220 and 250 °C for very short periods of reaction time (10 min). The as‐prepared materials were identified as Y(OH) 3 nanoparticles. The precursor materials with two types of morphologies, such as sphere and rod‐shaped particles were prepared at 220 and 250 °C within 10 min. The sizes of the as‐prepared sphere particles are 10–15 nm in diameter, whereas the rod‐shaped particles show 15–20 nm in diameter and 0.1–0.2 μm in lengths. The precursor materials were calcined at 500 and 800 °C for 5 h in air to obtain (3 mol‐%) Tm 3+ ‐doped Y 2 O 3 nanocrystals. For the characterization, XRD, FESEM, EDS and TG‐DTA were employed. The photoluminescence spectra of sphere and rod‐shaped particles show higher blue emission at 450 nm than the reference s le. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Publisher: Royal Society of Chemistry (RSC)
Date: 20-08-2014
DOI: 10.1039/C4TA03566F
Publisher: Elsevier BV
Date: 12-2014
DOI: 10.1016/J.WOMBI.2014.05.005
Abstract: Implementation of the Baby Friendly Health Initiative (BFHI) is associated with increases in breastfeeding initiation and duration of exclusive breastfeeding and 'any' breastfeeding. However, implementation of the BFHI is challenging. To identify and synthesise health care staff perceptions of the WHO/UNICEF BFHI and identify facilitators and barriers for implementation. Seven qualitative studies, published between 2003 and 2013 were analysed using meta-ethnographic synthesis. Three overarching themes were identified. First the BFHI was viewed variously as a 'desirable innovation or an unfriendly imposition'. Participants were passionate about supporting breastfeeding and improving consistency in the information provided. This view was juxtaposed against the belief that BFHI represents an imposition on women's choices, and is a costly exercise for little gain in breastfeeding rates. The second theme highlighted cultural and organisational constraints and obstacles to BFHI implementation including resource issues, entrenched staff practices and staff rationalisation of non-compliance. Theme three captured a level of optimism and enthusiasm amongst participants who could identify a dedicated and credible leader to lead the BFHI change process. Collaborative engagement with all key stakeholders was crucial. Health care staff hold variant beliefs and attitudes towards BFHI, which can help or hinder the implementation process. The introduction of the BFHI at a local level requires detailed planning, extensive collaboration, and an enthusiastic and committed leader to drive the change process. This synthesis has highlighted the importance of thinking more creatively about the translation of this global policy into effective change at the local level.
Publisher: Elsevier BV
Date: 05-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3RA42540A
Publisher: Elsevier BV
Date: 07-2010
Publisher: Elsevier BV
Date: 08-2017
Publisher: American Scientific Publishers
Date: 02-2010
Abstract: A solvothermal refluxing system containing of ethylene glycol and ethylene glycol-hexane mixed organic solvents were used to prepare Eu3+ doped Y2O3 nanocrystals via solvothermal refluxing reaction-calcinations method. In the presence of ethylene glycol, the reaction temperature required for the preparation of Y(OH)3 precursor crystal is 170 degrees C but in ethylene glycol-hexane mixed organic solvents, the synthesis temperature was reduced to 70 degrees C. The Y(OH)3 precursor particles were calcinated at 600-1200 degrees C in air to prepare nanosized Eu3+ doped Y2O3 red phosphor. The as prepared particles by refluxing in ethylene glycol followed by calcination showed 20-60 nm in diameter. For the characterization, XRD, TG-DTA, EDS, FTIR, TEM and PL measurements were employed. The as prepared s le by refluxing in ethylene glycol-hexane mixed solvents exhibited strong red emission around 610 nm under 254 nm xenon light excitation and photoluminescence property was compared with reference s le (5 mol% Eu3+:Y2O3) prepared via conventional co-precipitation method followed by calcinations at 800 degrees C for 5 h in air.
Publisher: American Chemical Society (ACS)
Date: 17-02-2012
DOI: 10.1021/NL202681B
Abstract: Novel ultrathin Li(2)MnSiO(4) nanosheets have been prepared in a rapid one pot supercritical fluid synthesis method. Nanosheets structured cathode material exhibits a discharge capacity of ~340 mAh/g at 45 ± 5 °C. This result shows two lithium extraction/insertion performances with good cycle ability without any structural instability up to 20 cycles. The two-dimensional nanosheets structure enables us to overcome structural instability problem in the lithium metal silicate based cathode materials and allows successful insertion/extraction of two complete lithium ions.
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8RA01281D
Abstract: Highly ordered and three-dimensional (3-D) mesoporous carbon materials were prepared through a nano-hard templating approach using FDU-12 silica with tunable pore sizes as a template, which was synthesized via a microwave-assisted method.
Publisher: Elsevier BV
Date: 05-2014
Publisher: Elsevier BV
Date: 03-2020
Publisher: Springer Science and Business Media LLC
Date: 05-02-2014
DOI: 10.1038/SREP03975
Abstract: Lithium-ion batteries offer promising opportunities for novel energy storage systems and future application in hybrid electric vehicles or electric vehicles. Cathode materials with high energy density are required for practical application. Herein, high-voltage LiCoPO 4 cathode materials with different shapes and well-developed facets such as nanorods and nanoplates with exposed {010} facets have been synthesized by a one-pot supercritical fluid (SCF) processing. The effect of different amines and their roles on the morphology-control has been investigated in detail. It was found that amine having long alkyl chain such as hexamethylenediamine played important roles to manipulate the shape of the nanocrystals by selective adsorption on the specific {010} facets. More importantly, the nanorods and nanoplates showed better electrochemical performance than that of nanoparticles which was attributed to their unique crystallographic orientation with short Li ion diffusion path. The present study emphasizes the importance of crystallographic orientation in improving the electrochemical performance of the high voltage LiCoPO 4 cathode materials for Li-ion batteries.
Publisher: Elsevier BV
Date: 2009
Publisher: AIP
Date: 2010
DOI: 10.1063/1.3529318
Publisher: Elsevier BV
Date: 10-2012
Publisher: American Chemical Society (ACS)
Date: 06-05-2011
DOI: 10.1021/IC101496B
Abstract: A new approach that uses mixed supercritical solvents of water/1-propanol and water/methanol (400 °C, 40 MPa) to prepare morphology-controlled precursor materials in a very short reaction time, such as 10 min, followed by calcinations has been developed to form Eu(3+):Y(2)O(3) microspheres of 2-3 μm in diameter or microcubes of 2-3 μm in side length, respectively. Eu(3+):Y(2)O(3) microspheres and microcubes exhibited strong red emission at 610 nm corresponding to (5)D(0) → (7)F(2) transition. The highest photoluminescence emission was obtained for the microspheres after calcination at 1000 °C for 1 h in air.
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2CC17234H
Abstract: Monodispersed Li(2)MnSiO(4) nanoparticles are synthesized via a supercritical solvothermal method at 300 °C for 5 min reaction time. The as-synthesized nanoparticles are free from impurities and have 15-20 nm diameter. After coating with conductive polymer, a discharge capacity of 313 mA h g(-1) is obtained for the first time because of nearly 2Li(+) reaction.
Publisher: IOP Publishing
Date: 08-09-2009
DOI: 10.1088/0957-4484/20/40/405606
Abstract: Solvothermal synthesis under supercritical conditions (400 degrees C) and high autogenous pressure (about 40 MPa), has been carried out for the direct preparation of nanocrystalline powders of CeO2, Ce(0.85)Zr(0.15)O2, Ce(0.75)Zr(0.25)O2, Ce(0.65)Zr(0.35)O2 and Ce(0.5)Zr(0.5)O2 which are characterized for applications as catalysts for oxygen storage in automotive catalysis. The synthesis was carried out in the presence of polyethylene glycol and water. For the characterization, x-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS) and the Brunauer-Emmet-Teller (BET) technique were employed. The oxygen storage capacity (OSC) of as-prepared and calcined s les without loading of noble metals was measured using thermogravimetric-differential thermal analysis (TG-DTA) at 600 degrees C with a continuous flow of CO-N2 gas and air alternately. Ce(0.5)Zr(0.5)O2 nanoparticles with a BET surface area of 102 m(2) g(-1) exhibited the highest OSC of 0.073 50 mol-O2/mol-CeO2. The OSC values obtained increased with increasing the amount of ZrO2 doping in the s les.
Publisher: IOP Publishing
Date: 07-07-2009
DOI: 10.1088/0957-4484/20/30/305302
Abstract: One-dimensional single crystalline rare earth ion (Tm(3+), Tb(+3), and Eu(3+)) doped Y (OH)(3) nanotubes with inner diameters of 20-110 nm, outer diameters of 50-140 nm, and 1-5 microm in length were prepared for the first time by a rapid hydrothermal method within a short reaction period (5 min) at subcritical temperature (320 degrees C) and high pressure (about 40 MPa). A temperature dependent nanostructure evolution study was performed under rapid hydrothermal conditions and the effects of other processing parameters such as concentration of KOH and reaction time were found to be key parameters for the formation of highly anisotropic crystal structures of rare earth hydroxide nanotubes. Rare earth ion (Tm(3+), Tb(+3), and Eu(3+)) doped Y(2)O(3) nanotubes can be obtained after calcinations above 450 degrees C. The luminescent property of rare earth doped Y(2)O(3) nanotubes was also explored and compared with reference s les prepared via a conventional co-precipitation method.
Publisher: Springer Netherlands
Date: 2013
Publisher: Springer Science and Business Media LLC
Date: 03-2006
Publisher: Oxford University Press (OUP)
Date: 06-11-2019
DOI: 10.1093/HMG/DDZ260
Abstract: Dynamin 2 (DNM2) encodes a ubiquitously expressed large GTPase with membrane fission capabilities that participates in the endocytosis of clathrin-coated vesicles. Heterozygous mutations in DNM2 are associated with two distinct neuromuscular disorders, Charcot–Marie–Tooth disease (CMT) and autosomal dominant centronuclear myopathy (CNM). Despite extensive investigations in cell culture, the role of dynamin 2 in normal muscle development is poorly understood and the consequences of DNM2 mutations at the molecular level in vivo are not known. To address these gaps in knowledge, we developed transgenic zebrafish expressing either wild-type dynamin 2 or dynamin 2 with either a CNM or CMT mutation. Taking advantage of the live imaging capabilities of the zebrafish embryo, we establish the localization of wild-type and mutant dynamin 2 in vivo, showing for the first time distinctive dynamin 2 subcellular compartments. Additionally, we demonstrate that CNM-related DNM2 mutations are associated with protein mislocalization and aggregation. Lastly, we define core phenotypes associated with our transgenic mutant fish, including impaired motor function and altered muscle ultrastructure, making them the ideal platform for drug screening. Overall, using the power of the zebrafish, we establish novel insights into dynamin 2 localization and dynamics and provide the necessary groundwork for future studies examining dynamin 2 pathomechanisms and therapy development.
Publisher: American Chemical Society (ACS)
Date: 25-04-2014
DOI: 10.1021/CM501452P
Publisher: Elsevier BV
Date: 07-2018
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C2RA22409G
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3RA42686F
Publisher: Elsevier BV
Date: 03-2010
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4RA01772B
Abstract: Supercritical fluid methods are proven to be very beneficial in controlling the size and shape of lithium battery materials. We hope that this review provides useful information on the production of these materials via supercritical fluid methods for energy storage applications, and that they could be extended for the synthesis of a variety of technologically potential materials.
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8RA07205A
Abstract: Structural defects, including point defects, dislocation and planar defects, significantly affect the physical and chemical properties of low-dimensional materials, such as layered compounds.
Publisher: Elsevier BV
Date: 03-2020
Publisher: American Chemical Society (ACS)
Date: 04-08-2016
DOI: 10.1021/ACS.NANOLETT.6B02593
Abstract: Exploring novel electrode materials is critical for the development of a next-generation rechargeable magnesium battery with high volumetric capacity. Here, we showed that a distinct amorphous molybdenum sulfide, being a coordination polymer of disulfide-bridged (Mo3S11) clusters, has great potential as a rechargeable magnesium battery cathode. This material provided good reversible capacity, attributed to its unique structure with high flexibility and capability of deformation upon Mg insertion. Free-terminal disulfide moiety may act as the active site for reversible insertion and extraction of magnesium.
Publisher: Wiley
Date: 08-10-2014
Abstract: Atomic-resolution imaging of the crystal defects of cathode materials is crucial to understand their formation and the correlation between the structure, electrical properties, and electrode performance in rechargeable batteries. The polytype, a stable form of varied crystal structure with uniform chemical composition, holds promise to engineer electronic band structure in nanoscale homojunctions.1-3 Analyzing the exact sites of atoms and the chemistry of the boundary in polytypes would advance our understanding of their formation and properties. Herein, the polytype and stacking faults in the lithium cobalt silicates are observed directly by aberration-corrected scanning transmission electron microscopy. The atomic-scale imaging allows clarification that the polytype is formed by stacking of two different close-packed crystal planes in three-dimensional space. The formation of the polytype was induced by Li-Co cation exchange, the transformation of one phase to the other, and their stacking. This finding provides insight into intrinsic structural defects in an important Li2 CoSiO4 Li-ion battery cathode.
Publisher: American Chemical Society (ACS)
Date: 05-2009
DOI: 10.1021/CG9002934
Publisher: Elsevier BV
Date: 12-2012
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C0CE00611D
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7TA06969C
Abstract: A simple and versatile method for the preparation of mesoporous carbon nitrides functionalized with highly dispersed chromium oxide nanoparticles by using MIL-100(Cr) for CO 2 and H 2 adsorption is reported.
No related grants have been discovered for Devaraju Murukanahally Kempaiah.