ORCID Profile
0000-0002-7127-7109
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2JM15048D
Publisher: Elsevier BV
Date: 07-2014
Publisher: Elsevier BV
Date: 08-2011
Publisher: Wiley
Date: 21-05-2019
Publisher: American Chemical Society (ACS)
Date: 09-02-2018
Abstract: Unidirectional graphene aerogels (UGAs) with tunable densities, degrees of alignment, and electrical conductivities are prepared by varying the average size of precursor graphene oxide (GO) sheets between 1.1 and 1596 μm
Publisher: Elsevier BV
Date: 05-2013
DOI: 10.1016/J.BIOS.2012.12.056
Abstract: In this work, we report a "turn-on" fluorescent strategy for the direct detection of Cu(2+) in solutions using molecular beacons (MBs) and graphene oxide (GO). MBs are special single-stranded DNA and carry fluorescence sources. GO is a new nanomaterial having remarkable physical properties. In the sensing system, GO was used as an efficient fluorescence quencher upon the adsorption of MBs, which reduced the background signal and made the detection method highly sensitive. In the presence of Cu(2+), the MBs were cut into short pieces and released by the GO, leading to fluorescence restoration. The detection limit of the sensing strategy was ∼50nM, which is sufficiently sensitive for practical applications. The sensing method also exhibited high selectivity in testing s les containing other metal ions. The application of the method for drinking water is demonstrated.
Publisher: American Chemical Society (ACS)
Date: 28-06-2011
DOI: 10.1021/NN2018683
Abstract: Monolayer graphene oxide (GO) sheets with sizes ranging from a few to ∼200 μm are synthesized based on a chemical method and are sorted out to obtain four different grades having uniform sizes. Transparent conductive films are produced using the ultralarge graphene oxide (UL-GO) sheets that are deposited layer-by-layer on a substrate using the Langmuir-Blodgett (LB) assembly technique. The density and degree of wrinkling of the UL-GO monolayers are turned from dilute, close-packed flat UL-GO to graphene oxide wrinkles (GOWs) and concentrated graphene oxide wrinkles (CGOWs) by varying the LB processing conditions. The method demonstrated here opens up a new avenue for high-yield fabrication of GOWs or CGOWs that are considered promising materials for hydrogen storage, supercapacitors, and nanomechanical devices. The films produced from UL-GO sheets with a close-packed flat structure exhibit exceptionally high electrical conductivity and transparency after thermal reduction and chemical doping treatments. A remarkable sheet resistance of ∼500 Ω/sq at 90% transparency is obtained, which outperforms the graphene films grown on a Ni substrate by chemical vapor deposition. The technique used in this work to produce transparent conductive UL-GO thin films is facile, inexpensive, and tunable for mass production.
Publisher: Elsevier BV
Date: 09-2012
Publisher: Elsevier BV
Date: 05-2010
Publisher: American Chemical Society (ACS)
Date: 11-07-2018
Abstract: Hexagonal boron nitride (h-BN) has tremendous potential for dielectric energy storage by rationally assembling with graphene. We report the fabrication of microlaminate composites consisting of alternating reduced graphene oxide (rGO) and h-BN nanosheets embedded in a polyurethane (PU) matrix using a novel, two-step bidirectional freeze casting process. Porous, highly-aligned rGO-PU aerogels having ultrahigh dielectric constants with relatively high dielectric losses and low dielectric strengths are fabricated by initial freeze casting. The losses are suppressed, whereas the dielectric strengths are restored by assembling the porous rGO-PU skeleton with electrically insulating BN-PU tunneling barrier layers in the second freeze casting routine. The ligaments bridging the conductive rGO-PU layers are effectively removed by the BN-PU barrier layers, eliminating the current leakage in the transverse direction. The resultant rGO-PU/BN-PU microlaminate composites deliver a remarkable dielectric constant of 1084 with a low dielectric loss of 0.091 at 1 kHz. By virtue of synergy arising from both the rGO-PU layers with a high dielectric constant and the BN-PU barrier layers with a high dielectric strength, the microlaminate composites present a maximum energy density of 22.7 J/cm
Publisher: American Chemical Society (ACS)
Date: 04-12-2012
DOI: 10.1021/NN303904Z
Abstract: This study demonstrates that large-size graphene oxide (GO) sheets can impart a tremendous positive impact on self-alignment, electrical conductivity, and mechanical properties of graphene papers. There is a remarkable, more than 3-fold improvement in electrical conductivity of the papers made from ultralarge GO sheets (with an average area of 272.2 μm(2)) compared to that of the small GO counterpart (with an average area of 1.1 μm(2)). The corresponding improvements in Young's modulus and tensile strength are equally notable, namely 320% and 280%, respectively. These improvements of bulk properties due to the large GO sheets are correlated to multiscale elemental and structural characteristics of GO sheets, such as the content of carboxyl groups on the GO edge, C/O ratio and Raman D/G-band intensity ratio of GO on the molecular-scale, and the degree of dispersion and stacking behavior of GO sheets on the microscale. The graphene papers made from larger GO sheets exhibit a closer-stacked structure and better alignment as confirmed by the fast Fourier transform analysis, to the benefits of their electrical conductivity and mechanical properties. The molecular dynamics simulation further elucidates that the enhanced intersheet interactions between large GO sheets play a key role in improving the Young's modulus of GO papers. The implication is that the said properties can be further improved by enhancing the intersheet stress transfer and electrical conduction especially through the thickness direction.
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7MH00984D
Abstract: A CVD-grown high-density 3D multilayer graphene web (MGW) is used as the filler for polymer nanocomposites, delivering exceptional electrical and thermal conductivities with outstanding fracture toughness.
Publisher: Elsevier BV
Date: 08-2013
Publisher: Elsevier BV
Date: 10-2017
Publisher: Wiley
Date: 24-03-2018
Publisher: Springer New York
Date: 2015
Publisher: Wiley
Date: 12-03-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2JM34870E
Publisher: Elsevier BV
Date: 06-2013
Publisher: Elsevier BV
Date: 06-2020
Publisher: Wiley
Date: 03-06-2011
Publisher: Elsevier BV
Date: 11-2011
Publisher: American Chemical Society (ACS)
Date: 24-12-2018
Abstract: Advanced wearable strain sensors with high sensitivity and stretchability are an essential component of flexible and soft electronic devices. Conventional metal- and semiconductor-based strain sensors are rigid, fragile, and opaque, restricting their applications in wearable electronics. Graphene-based percolative structures possess high flexibility and transparency but lack high sensitivity and stretchability. Inspired by the highly flexible spider web architecture, we propose semitransparent, ultrasensitive, and wearable strain sensors made from an elastomer-filled graphene woven fabric (E-GWF) for monitoring human physiological signals. The highly flexible elastomer microskeleton and the hierarchical structure of a graphene tube offer the strain sensor with both excellent sensing and switching capabilities. Two different types of E-GWF sensors, including freestanding E-GWF and E-GWF olydimethylsiloxane (PDMS) composites, are developed. When their structure is controlled and optimized, the E-GWF strain sensors simultaneously exhibit extraordinary characteristics, such as a high gauge factor (70 at 10% strain, which ascends to 282 at 20%) in respect to other semitransparent or transparent strain sensors, a broad sensing range up to 30%, and excellent linearity. The E-GWF/PDMS composite sensor shows a unique reversible switching behavior at a high strain level of 30-50%, making it a suitable material for fast and reversible strain switching required in many early warning systems. With a view to real-world applications of these sensors and switches, we demonstrate human motion detection and switch controls of light-emitting-diode l s and liquid-crystal-display circuits. Their unique structure and capabilities can find a wide range of practical applications, such as health monitoring, medical diagnosis, early warning systems for structural failure, and wearable displays.
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7NH00147A
Abstract: We report dual-functional wearable strain sensors and switches with tunable sensitivities and switching capabilities for wearable wireless health monitoring.
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2JM30590A
Publisher: Elsevier BV
Date: 12-2010
Publisher: American Scientific Publishers
Date: 11-2010
Abstract: In this study, the effects of chemical functionalization on the elastic properties of graphene sheets are investigated by using molecular dynamics (MD) and molecular mechanics (MM) simulations. The influences of the degree of functionalization, which is defined as the ratio of the number of the total sp3-hybridized atoms to the number of the total carbon atoms of the graphene sheet, the chirality of graphene sheets, the molecular structure and molecular weight of functional groups on Young's modulus are studied. The dependence of shear modulus and wrinkling properties on the functional groups are also investigated. The simulation results indicate that Young's modulus depends strongly on the degree of functionalization and the molecular structure of the functional groups, while the effects of chirality of the graphene sheets and the molecular weight of the functional groups are negligible. The chemical functionalization also reduces the shear modulus and critical strain, beyond which the wrinkling instability occurs.
Publisher: Springer International Publishing
Date: 2014
No related grants have been discovered for Qingbin Zheng.