The Experts below are selected from a list of 72180 Experts worldwide ranked by ideXlab platform
Jin Suk Chung - One of the best experts on this subject based on the ideXlab platform.
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highly conductive poly methyl methacrylate pmma reduced Graphene Oxide composite prepared by self assembly of pmma latex and Graphene Oxide through electrostatic interaction
ACS Applied Materials & Interfaces, 2012Co-Authors: Viet Hung Pham, Thanh Truong Dang, Seung Hyun Hur, Eui Jung Kim, Jin Suk ChungAbstract:We report a simple, environmentally friendly approach for preparing highly conductive poly(methyl methacrylate)–reduced Graphene Oxide (PMMA-RGO) composites by self-assembly of positively charged PMMA latex particles and negatively charged Graphene Oxide sheets through electrostatic interactions, followed by hydrazine reduction. The PMMA latex was prepared by surfactant-free emulsion polymerization using a cationic free radical initiator, which created the positive charges on the surface of the PMMA particle. By mixing PMMA latex with a Graphene Oxide dispersion, positively charged PMMA particles easily assembled with negatively charged Graphene Oxide sheets through electrostatic interaction. The obtained PMMA-RGO exhibited excellent electrical properties with a percolation threshold as low as 0.16 vol % and an electrical conductivity of 64 S/m at only 2.7 vol %. Moreover, the thermomechanical properties of PMMA-RGO were also significantly improved. The storage modulus of PMMA-RGO increased by about 30% a...
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the role of Graphene Oxide content on the adsorption enhanced photocatalysis of titanium diOxide Graphene Oxide composites
Chemical Engineering Journal, 2011Co-Authors: Thuyduong Nguyenphan, Viet Hung Pham, Eun Woo Shin, Hai Dinh Pham, Jin Suk ChungAbstract:Abstract Titanium diOxide/Graphene Oxide composites were prepared using a simple colloidal blending method. Superior adsorption and photocatalysis performance under both UV and visible radiation were achieved in the presence of the composites rather than in pure TiO2. Gradually increasing the content of Graphene Oxide up to 10 wt% promoted the removal efficiency and correspondingly, facilitated the photodegradation rate of methylene blue. The good photocatalytic performance on the TiO2–Graphene Oxide composite systems irrespective of light sources could be attributed to a synergy effects including the increase in specific surface area with Graphene Oxide amount as well as the formation of both π–π conjugations between dye molecules and aromatic rings and the ionic interactions between methylene blue and oxygen-containing functional groups at the edges or on the surfaces of carbon-based nanosheets. Graphene Oxide worked as the adsorbent, electron acceptor and photosensitizer to efficiently enhance the dye photodecomposition.
Alexandre Velhinho - One of the best experts on this subject based on the ideXlab platform.
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Graphene Oxide reinforced aluminium matrix nanostructured composites fabricated by accumulative roll bonding
Composites Part B-engineering, 2019Co-Authors: Francisco Ferreira, Isabel M P L V O Ferreira, Edgar Camacho, F Lopes, A C Marques, Alexandre VelhinhoAbstract:Abstract Accumulative Roll Bonding (ARB) was used to fabricate Graphene Oxide-reinforced Al-matrix composites. Graphene Oxide reinforcement was suspended in a stabilized aqueous solution and applied, prior to each ARB cycle, through airgun spraying. Different concentrations (Graphene Oxide/milipore water) were used and for each concentration, samples produced have undergone up to 5 rolling cycles. Optical and electron scanning microscopies were used for microstructural characterization which revealed a non-homogenous deformation of the layers across the composite's thickness. Although the presence of Graphene-Oxide promoted an increase in the microhardness, higher values were obtained with its lowest concentration for similar samples. The number of ARB cycles and the direction of the tested sections also influenced the microhardness results since the 5-cycle samples and the rolling direction sections for all the samples achieved higher hardness results. Graphene Oxide revealed to be a major contributor to the increase of stiffness during bending of the tested samples.
Xin Zhao - One of the best experts on this subject based on the ideXlab platform.
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a low temperature method to produce highly reduced Graphene Oxide
Nature Communications, 2013Co-Authors: Hongbin Feng, Rui Cheng, Xin Zhao, Xiangfeng DuanAbstract:The chemical reduction of Graphene Oxide can provide large quantities of reduced Graphene Oxide for potential application in electronics and composite materials. Feng et al. report a highly efficient low-temperature one-pot reduction of Graphene Oxide that uses sodium-ammonia solution as the reducing agent.
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Ultrafast carrier dynamics and saturable absorption of solution-processable few-layered Graphene Oxide
Applied Physics Letters, 2011Co-Authors: Xin Zhao, Zhi-bo Liu, Weibo Yan, Xiao-liang Zhang, Yongsheng Chen, Jianguo TianAbstract:Ultrafast carrier dynamics and saturable absorption of few-layered Graphene Oxide, well-dispersed in organic solvent, are studied using femtosecond pump-probe and Z-scan techniques. The results demonstrate that few-layered Graphene Oxide has a fast energy relaxation of hot carriers and strong saturable absorption, which is comparable with that of reduced Graphene Oxide. Fast carrier relaxation combined with well solution processing capability arises from the large fraction of sp2 carbon atom inside the few-layered Graphene Oxide sheet together with oxidation mainly existing at the edge areas. This superiority of few-layered Graphene Oxide will facilitate potential applications of Graphene for ultrafast photonics.
Shiping Yang - One of the best experts on this subject based on the ideXlab platform.
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Graphene Oxide hyaluronic acid nanometer drug carrier material preparation method and application of Graphene Oxide hyaluronic acid nanometer drug carrier material
2012Co-Authors: Huixia Wu, Yapei Wang, Bo Zeng, Shiping YangAbstract:The invention discloses a Graphene Oxide/hyaluronic acid nanometer drug carrier material. The Graphene Oxide/hyaluronic acid nanometer drug carrier material is characterized in that adipic acid hydrazide is covalently connected on the surface of monolayer Graphene Oxide, targeted molecular hyaluronic acid is further coupled by amino groups on the adipic acid hydrazide; the monolayer Graphene Oxide is 0.5-2nm thick; and the average size of the Graphene Oxide/hyaluronic acid nanometer drug carrier material is 50-300nm. According to the Graphene Oxide/hyaluronic acid nanometer drug carrier material provided by the invention, the hyaluronic acid is covalently modified on the surface of the Graphene Oxide and has a good targeting property; besides, the modified Graphene Oxide has good biocompatibility and benefits the biological application of the material; and moreover, the obtained functionalized nanometer material is expected to be used as a drug transmission carrier.
Francisco Ferreira - One of the best experts on this subject based on the ideXlab platform.
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Graphene Oxide reinforced aluminium matrix nanostructured composites fabricated by accumulative roll bonding
Composites Part B-engineering, 2019Co-Authors: Francisco Ferreira, Isabel M P L V O Ferreira, Edgar Camacho, F Lopes, A C Marques, Alexandre VelhinhoAbstract:Abstract Accumulative Roll Bonding (ARB) was used to fabricate Graphene Oxide-reinforced Al-matrix composites. Graphene Oxide reinforcement was suspended in a stabilized aqueous solution and applied, prior to each ARB cycle, through airgun spraying. Different concentrations (Graphene Oxide/milipore water) were used and for each concentration, samples produced have undergone up to 5 rolling cycles. Optical and electron scanning microscopies were used for microstructural characterization which revealed a non-homogenous deformation of the layers across the composite's thickness. Although the presence of Graphene-Oxide promoted an increase in the microhardness, higher values were obtained with its lowest concentration for similar samples. The number of ARB cycles and the direction of the tested sections also influenced the microhardness results since the 5-cycle samples and the rolling direction sections for all the samples achieved higher hardness results. Graphene Oxide revealed to be a major contributor to the increase of stiffness during bending of the tested samples.
