The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Jinhai Guo - One of the best experts on this subject based on the ideXlab platform.
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preparation of cnt Hybridized Carbon fiber by aerosol assisted chemical vapor deposition
Journal of Materials Science, 2012Co-Authors: Jinhai GuoAbstract:The purpose of this article is to find a way to prepare multiscale material, namely, Carbon nanotube-Hybridized Carbon fiber (CNT/CF) with a low degradation of mechanical properties. Using a facile aerosol-assisted chemical vapor deposition method, a novel route was described to fabricate CNT/CF. The essential of this technique was in situ formation of catalyst (Fe) nanoparticles via pyrolysis of ferrocene–acetone aerosol right before CNTs growth. Through optimizing aerosol supply and process parameters, a uniform coverage of CNTs was successfully grafted onto the Carbon fiber surface to obtain a multiscale (hierarchical) structure. The strong anchorage between the as-synthesized CNTs and Carbon fiber substrate was confirmed by ultrasonic bath treatment. Compared with the as-received Carbon fibers, single fiber tensile testing results demonstrated that the tensile strengths of CNT-Hybridized Carbon fiber slightly degraded within 10% at all the correspondingly given gauge lengths.
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preparation and characterization of Carbon nanotube Hybridized Carbon fiber to reinforce epoxy composite
Materials & Design, 2012Co-Authors: Jinhai Guo, Yu YangAbstract:Abstract The multiscale Carbon nanotube-Hybridized Carbon fiber was prepared by a newly developed aerosol-assisted chemical vapour deposition. Scanning electron microscopy and transmission electron microscope were carried out to characterize this multiscale material. Compared with the original Carbon fibers, the fabrication of this hybrid fiber resulted in an almost threefold increase of BET surface area to reach 2.22 m 2 /g. Meanwhile, there was a slight degradation of fiber tensile strength within 10%, while the fiber modulus was not significantly affected. The interfacial shearing strength of a Carbon fiber-reinforced polymer composite with Carbon nanotube-Hybridized Carbon fiber and an epoxy matrix was determined from the single fiber pull-out tests of microdroplet composite. Due to an efficient increase of load transfer at the fiber/matrix interfaces, the interracial shear strength of composite reinforced by Carbon nanotube-Hybridized Carbon fiber is almost 94% higher than that of one reinforced by the original Carbon fiber. Based on the fractured morphologies of the composites, the interfacial reinforcing mechanisms were discussed through proposing different types of Carbon nanotube fracture modes along with fiber pulling out from epoxy composites.
Norio Shibata - One of the best experts on this subject based on the ideXlab platform.
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fluorobissulfonylmethyl iodides an efficient scaffold for halogen bonding catalysts with an sp3 Hybridized Carbon iodine moiety
ACS Catalysis, 2018Co-Authors: Kohei Matsuzaki, Hiroto Uno, Etsuko Tokunaga, Norio ShibataAbstract:The halogen-bond donors FBSM-I and FBDT-I, which contain an sp3-Hybridized Carbon–iodine (Csp3–I) moiety, were designed and synthesized. The highly electron-withdrawing nature of the fluorobissulfonyl-methane scaffold leads to the generation of σ-holes on the surface of the iodine atoms in FBSM-I and FBDT-I. Mukaiyama aldol reactions and hydrogen-transfer reductions are efficiently catalyzed by FBSM-I and FBDT-I under neutral and mild reaction conditions. The driving force for these transformations should be the halogen bonding induced by FBSM-I and FBDT-I, which was confirmed by DFT calculations, single-crystal X-ray diffraction analyses, and NMR titrations.
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Fluorobissulfonylmethyl Iodides: An Efficient Scaffold for Halogen Bonding Catalysts with an sp3‑Hybridized Carbon–Iodine Moiety
2018Co-Authors: Kohei Matsuzaki, Hiroto Uno, Etsuko Tokunaga, Norio ShibataAbstract:The halogen-bond donors FBSM-I and FBDT-I, which contain an sp3-Hybridized Carbon–iodine (Csp3–I) moiety, were designed and synthesized. The highly electron-withdrawing nature of the fluorobissulfonyl-methane scaffold leads to the generation of σ-holes on the surface of the iodine atoms in FBSM-I and FBDT-I. Mukaiyama aldol reactions and hydrogen-transfer reductions are efficiently catalyzed by FBSM-I and FBDT-I under neutral and mild reaction conditions. The driving force for these transformations should be the halogen bonding induced by FBSM-I and FBDT-I, which was confirmed by DFT calculations, single-crystal X-ray diffraction analyses, and NMR titrations
Hongyu Zhang - One of the best experts on this subject based on the ideXlab platform.
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tunable hydrogen separation in sp sp2 Hybridized Carbon membranes a first principles prediction
Journal of Physical Chemistry C, 2012Co-Authors: Hongyu Zhang, Mingwen Zhao, Meng Zhang, Lixia Zhao, Xiaojuan Feng, Youhua LuoAbstract:First-principles calculations are carried out to investigate the hydrogen separation characteristics of two-dimensional Carbon allotropes consisting of sp- and sp2-Hybridized Carbon atoms, i.e., graphyne, graphdiyne, and rhombic-graphyne. The selectivities for H2 over several gas molecules, including CO, N2, and CH4, are found to be sensitive to the pore sizes and shapes. The penetration barriers generally decrease exponentially with the pore sizes. Our results reveal that graphyne with small pores is unsuitable for the purpose of hydrogen separation. Graphdiyne, with larger pores, exhibits a high selectivity (109) for hydrogen over large gas molecules such as CH4, but a relatively low selectivity (103) over small molecules such as CO and N2. The large differences in diffusion barriers for molecules penetration through a rhombic-graphyne monolayer, which possesses pore size in between that of graphyne and graphdiyne, lead to a high selectivity (>1016) for hydrogen separation from the others. The results s...
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high mobility and high storage capacity of lithium in sp sp2 Hybridized Carbon network the case of graphyne
Journal of Physical Chemistry C, 2011Co-Authors: Hongyu Zhang, Mingwen Zhao, Zhenhai Wang, Xuejuan Zhang, Xiangdong LiuAbstract:We have carried out first-principles calculations to explore the energetics and dynamics of Li in graphyne, a novel Carbon allotrope consisting of sp–sp2 Hybridized Carbon atoms, relevant for anode lithium intercalation in rechargeable Li-ion batteries. In contrast to graphite where Li diffusion is confined in the interlayer space (in-plane diffusion), the unique atomic arrangement and electronic structures enable both in-plane and out-plane diffusion of Li ions in graphyne with moderate barriers, 0.53–0.57 eV. The highest Li intercalation density in graphyne can be LiC4, exceeding the up limit of LiC6 in the commonly used graphite. The high lithium mobility and high storage capacity make graphyne a promising candidate for the anode material in battery applications.
Guoqing Ning - One of the best experts on this subject based on the ideXlab platform.
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sp2 and sp3 Hybridized Carbon materials as catalysts for aerobic oxidation of cyclohexane
Catalysis Science & Technology, 2013Co-Authors: Yonghai Cao, Xianyu Luo, Feng Peng, Hongjuan Wang, Guoqing NingAbstract:The catalytic properties of sp2- and sp3-Hybridized Carbons, represented by graphene and diamond, in the selective oxidation of cyclohexane were investigated to understand the structure dependence of Carbon materials in the reaction. sp2 Carbons showed the higher activity than sp3 Carbons. The highest activity was obtained over mesoporous graphene, a representative sp2-Hybridized Carbon, yielding a weight-normalized activity of 162.6 mmol g−1 h−1. The excellent performance of sp2 Carbons was rationalized by their ability to catalyze the decomposition of peroxide intermediates, such as cyclohexyl hydroperoxide, which promoted the oxidative reaction to produce cyclohexanol and cyclohexanone.
Zhao Zhang - One of the best experts on this subject based on the ideXlab platform.
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photoluminescent lignin Hybridized Carbon quantum dots composites for bioimaging applications
International Journal of Biological Macromolecules, 2019Co-Authors: Bailiang Xue, Yang Yang, Yongchang Sun, Jinshuan Fan, Zhao ZhangAbstract:Abstract Carbon quantum dots (CQDs) have attracted considerable interests because of their unique luminescence properties and promising applications in bioimaging. Lignin Hybridized CQDs (L-CQDs) are facilely synthesized by one-pot hydrothermal method with different molar ratios of citric acid and ethanediamine. The morphology and chemical structures of L-CQDs are investigated by TEM, FT-IR, XPS, 2D-HSQC NMR spectra. The resultant L-CQDs with near spherical morphology are less than 10 nm in diameter, which are essentially composed of main interunit linkages and aromatic ring structures. The L-CQDs exhibit the excitation-dependent photoluminescence behavior with emission maximum ranging from 454 to 535 nm under excitation at 375–460 nm. The maximum emission of the L-CQDs red-shift to a longer wavelength with a decrease in intensity as the excitation wavelengths are gradually increased. L-CQDs show the low cytotoxicity and good cellular biocompatibility, demonstrating the great potential of the L-CQDs for bioimaging applications.
