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91.
We provide a novel strategy to eliminate the epoxy group from the basal plane of graphene platelets. Given that the current reduction methods are unsatisfactory to clean the epoxides or sometimes cause undesirable structure deformations, the proposed strategy restores the original hexagonal carbon network without creating other new defects. To the best of our knowledge, the electric field mediated graphene oxide (GO) reduction has not yet been systematically investigated. The capability would permit the improvement of existing GO reduction methods and assist in the fabrication of high‐quality graphitic materials. © 2012 Wiley Periodicals, Inc. 相似文献
92.
The electronic and optical properties of different stacked multilayer SiC and GeC are investigated with and without external electric field (EEF). The band gaps of multilayer SiC and GeC are found smaller than that of monolayer SiC and GeC due to the interlayer coupling effect. When EEF is applied, the direct band gaps (ΔK–M) of multilayer SiC and direct band gaps (ΔK–K) of multilayer GeC all turn to indirect band gaps (ΔK–G) as the band at the G point drops dramatically toward zero. The imaginary part ε2(ω)s of multilayer SiC and GeC show that new absorption peaks between 2–5 eV appear when the polarized direction is perpendicular to the layer plane, and new absorption peaks in infrared region appear as the EEF is higher than a certain point when the polarized direction is parallel to the layer plane. Our calculations reveal that different stacking sequences and EEF can provide a wide tunable band structures and optical properties for multilayer SiC and GeC. 相似文献
93.
Formation of homogeneous nanocomposite films at ambient temperature via miniemulsion polymerization using graphene oxide as surfactant 下载免费PDF全文
Yasemin Fadil S. H. C. Man Florent Jasinski Hideto Minami Stuart C. Thickett Per B. Zetterlund 《Journal of polymer science. Part A, Polymer chemistry》2017,55(14):2289-2297
A convenient and industrially scalable method for synthesis of homogeneous nanocomposite films comprising poly(styrene‐stat‐butyl acrylate) and nanodimensional graphene oxide (GO) or reduced GO (rGO) is presented. Importantly, the nanocomposite latex undergoes film formation at ambient temperature, thus alleviating any need for high temperature or high pressure methods such as compression molding. The method entails synthesis of an aqueous nanocomposite latex via miniemulsion copolymerization relying on nanodimensional GO sheets as sole surfactant, followed by ambient temperature film formation resulting in homogeneous film. For comparison, a similar latex obtained by physical mixing of a polymer latex with an aqueous GO dispersion results in severe phase separation, illustrating that the miniemulsion approach using GO as surfactant is key to obtaining homogeneous nanocomposite films. Finally, it is demonstrated that the GO sheets can be readily reduced to rGO in situ by heat treatment of the film. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 2289–2297 相似文献
94.
《中国化学》2017,35(9):1445-1451
Graphene oxide (GO ) and its functionalized derivatives have attracted increasing attention in medical treatment. Herein, a reduction sensitive PEI‐GO ‐SS ‐TPP was synthesized for photodynamic therapy. More than 80% porphyrin release was observed in the presence of 10 mmol•L−1 DTT in one day. The confocal laser scanning microscopy confirmed that the cell uptake efficiency of PEI‐GO‐SS‐TPP was remarkably enhanced as compared to free porphyrin which was significantly dependent on incubation time. For photodynamic therapy, GSH‐OEt could effectively increase the photodynamic therapy efficiency of PEI‐GO ‐SS ‐TPP . Compared with free porphyrin, the toxicity from PEI‐GO ‐SS ‐TPP is much higher with a low IC50 (2.1 µg/mL ) value. All results indicate that the PEI‐GO ‐SS ‐TPP PSs are promising for photodynamic therapy. 相似文献
95.
《应用有机金属化学》2017,31(11)
An efficient solid‐supported catalyst for the Huisgen [3 + 2] cycloaddition reaction between azides and alkynes was prepared from copper(I) iodide and 1,2,3‐triazole‐functionalized graphene oxide. This catalyst was then used for the efficient synthesis of β‐hydroxy‐1,2,3‐triazoles giving access to these products in excellent yields. In this protocol, the catalyst was shown to have high activity, air‐stability and recyclability. The formation of copper triazolide is very straightforward and energetically desirable. The catalyst can be isolated from copper‐catalysed azide–alkyne cycloaddition reactions. 相似文献
96.
《应用有机金属化学》2017,31(8)
Graphene oxide was functionalized with benzimidazole for palladium immobilization. The resultant graphene–benzimidazole‐supported palladium composite (G‐BI‐Pd) was characterized using infrared and Raman spectroscopies, transmission electron microscopy and energy‐dispersive X‐ray spectroscopy. G‐BI‐Pd showed excellent catalytic activity and fast reaction kinetics in the aqueous‐phase Suzuki–Miyaura reaction of aryl iodides and bromides with phenylboronic acid under relatively mild conditions (5–25 min, 80 °C). The catalyst can be used several times without any significant loss of its catalytic activity. 相似文献
97.
98.
Harshal P. Mungse Niharika Bhakuni Deependra Tripathi Om P. Sharma Bir Sain Om P. Khatri 《Journal of Physical Organic Chemistry》2014,27(12):944-951
Graphene oxide (GrO) prepared by the Hummers method was separated into three different fractions (GrO5000, GrO2000, and GrOres) on the basis of their dispersion stability in the water. Infrared, nuclear magnetic resonance, X‐ray photoelectron spectroscopy, and elemental analyses revealed that GrO5000 possesses a high degree of oxygen functionalities including phenolic, carboxylic, and ?OSO2H groups, compared with the other fractions. The GrO5000 was found to be a highly efficient and reusable solid catalyst for the esterification of various carboxylic acids with a variety of alcohols to furnish corresponding esters in high to excellent yields. The catalytic activity of the GrO5000 was attributed to the ability of highly polar GrO5000 scaffold to adsorb/attract reactants, where the acid functionalities of GrO5000 facilitated the esterification process efficiently. The chemical and structural features of GrO5000 were discussed to understand the improved catalytic activity compared with GrO2000 and conventional solid acid catalysts. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
99.
100.