A procedure for purification of single walled carbon nanotubes(SWNTs) grown by the chemical vapour deposition(CVD) of carbon monooxide has been developed. Based on the result from TGA/DTA of as prepared sample, the ...A procedure for purification of single walled carbon nanotubes(SWNTs) grown by the chemical vapour deposition(CVD) of carbon monooxide has been developed. Based on the result from TGA/DTA of as prepared sample, the oxidation temperature was determined. The process included sonication, oxidation and acid washing steps. The purity and yield after purification were determined and estimated by TEM. Moreover, for the first time, a loop structure for CVD SWNTs has been observed.展开更多
A series of MCM 41 molecular sieves have been prepared on an industrial scale, and the effect of preparation factors such as aging temperature, pH values on the structure and pore distribution of the MCM 41 product ...A series of MCM 41 molecular sieves have been prepared on an industrial scale, and the effect of preparation factors such as aging temperature, pH values on the structure and pore distribution of the MCM 41 product have been studied by using X ray diffraction(XRD), thermogravimetric(TG) and electron microscopy(TEM). It is shown that the pH values have a significant effect on the crystallinity of the synthesized product. Under proper conditions, the MCM 41 prepared on an industrial scale has the same performance as the samples prepared on an Lab scale. The prepared MCM 41 was used as a modifier of zeolite Y for fluid catalytic cracking(FCC) of residual oil. It is shown that the addition of the MCM 41 in the zeolite Y catalyst increases the pore size, and surface area of the catalysts, which helps to increase the yield of gasoline and diesel and decrease the production of gaseous product and carbon deposition in the catalyst. The better performance of the MCM 41 modified zeolite Y catalyst is believed to be due to its adjustment on the acidity and increase of the pore size.展开更多
WS2 nanotubes have been filled and intercalated by molten phase caesium iodide.The presence of caesium iodide inside the WS_(2) nanotubes has been determined using high-resolution transmission electron microscopy(HRTE...WS2 nanotubes have been filled and intercalated by molten phase caesium iodide.The presence of caesium iodide inside the WS_(2) nanotubes has been determined using high-resolution transmission electron microscopy(HRTEM)coupled with electron energy-loss spectroscopy(EELS)and energy-dispersive X-ray spectroscopy(EDS).Noticeably,a Moirépattern was observed due to the interference between encapsulated CsI and WS_(2) layers.The intercalation of CsI into the host concentric WS2 lattices resulted in an increase in the interplanar spacing.展开更多
文摘A procedure for purification of single walled carbon nanotubes(SWNTs) grown by the chemical vapour deposition(CVD) of carbon monooxide has been developed. Based on the result from TGA/DTA of as prepared sample, the oxidation temperature was determined. The process included sonication, oxidation and acid washing steps. The purity and yield after purification were determined and estimated by TEM. Moreover, for the first time, a loop structure for CVD SWNTs has been observed.
文摘A series of MCM 41 molecular sieves have been prepared on an industrial scale, and the effect of preparation factors such as aging temperature, pH values on the structure and pore distribution of the MCM 41 product have been studied by using X ray diffraction(XRD), thermogravimetric(TG) and electron microscopy(TEM). It is shown that the pH values have a significant effect on the crystallinity of the synthesized product. Under proper conditions, the MCM 41 prepared on an industrial scale has the same performance as the samples prepared on an Lab scale. The prepared MCM 41 was used as a modifier of zeolite Y for fluid catalytic cracking(FCC) of residual oil. It is shown that the addition of the MCM 41 in the zeolite Y catalyst increases the pore size, and surface area of the catalysts, which helps to increase the yield of gasoline and diesel and decrease the production of gaseous product and carbon deposition in the catalyst. The better performance of the MCM 41 modified zeolite Y catalyst is believed to be due to its adjustment on the acidity and increase of the pore size.
基金This work was supported by the Israel Science Foundation,European Research Council(ERC)grant(No.INTIF 226639)H.Perlman Foundation and the Cherna Moskowitz Center for Nano and Bio-Nano imaging.We thank Dr.Rita Rosentsveig for the supply of WS_(2)inorganic nanotubes.G.T.acknowledges support through FP7 European Community Marie Curie European Reintegration Grant(ERG)(No.PERG04-GA-2008-239303)+1 种基金B.B.a contract from Ministry of Science and Innovation(Ministerio de Ciencia e Innovación,MICINN)Spain.S.Y.H was supported by a Samsung Corporation fellowship(2005-2009)B.G.D.is a Royal Society-Wolfson Research Merit Award recipient and is also supported by an Engineering and Physical Sciences Research Council of the UK(EPSRC)Platform Grant(No.EPSRC EP/E000614/1).
文摘WS2 nanotubes have been filled and intercalated by molten phase caesium iodide.The presence of caesium iodide inside the WS_(2) nanotubes has been determined using high-resolution transmission electron microscopy(HRTEM)coupled with electron energy-loss spectroscopy(EELS)and energy-dispersive X-ray spectroscopy(EDS).Noticeably,a Moirépattern was observed due to the interference between encapsulated CsI and WS_(2) layers.The intercalation of CsI into the host concentric WS2 lattices resulted in an increase in the interplanar spacing.
