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A review is given on the fundamental studies of gas-carbon reactions using electronic structure methods in the last several decades. The three types of electronic structure methods including semi-empirical, ab initio and density functional theory methods are briefly introduced first, followed by the studies on carbon reactions with hydrogen and oxygen-containing gases (non-catalysed and catalysed)...
Chemical vapour infiltration is simulated by deposition of pyrolytic carbon on planar boron nitride substrates and carbon fibers in a hot-wall tubular reactor at about 1100 o C for varied pressure and flow-velocity of methane. The degree of orientation of the deposited graphite-like domains can be monitored via orientation and temperature dependence of the electron spin resonance parameters...
An investigation of the impact of strong oxidation with HNO 3 on the porosity and adsorption characteristics of char and activated carbons, derived from corncobs, is presented. Texture parameters, as obtained from N 2 adsorption at 77 K, showed a considerable decrease in surface area of the activated carbons with enhanced pore widening. The extent of porosity modification was found...
In this paper we report and interpret the effectiveness of different bulk metal catalyst preparations and of various components within reactive gas mixtures for carbon nanotube (CNT) synthesis. The combined catalyst precursor and supporting material is type 304 stainless steel mesh. The steel mesh keenly illustrates the net effect of different pretreatments upon the catalyst because of its resistance...
A new synthetic medium for the production of C 60 has been found that does not produce soot. C 60 was produced in the liquid phase of an aerosol of precursor soot at 700 o C. The precursor soot aerosol, a high temperature stable form of hydrocarbon, was produced by pyrolysis of acetylene at atmospheric pressure in a flow tube reactor. At 700 o C, the effluent...
The evolution of the electrochemical double layer capacitance of glassy carbon during thermochemical gas phase oxidation was studied with electrochemical impedance spectroscopy. Particular attention was paid to the initial oxidation stage, during which the capacitance grows exponentially. This stage could be experimentally assessed by lowering the reaction temperature and oxidant partial pressure...
A C 60 polymer has been characterized for the first time with respect to impurity content and ferromagnetic properties by laterally resolved particle induced X-ray emission (PIXE), superconducting quantum interference device (SQUID) and magnetic force microscopy (MFM) in order to detect intrinsic ferromagnetic domains. In parts of the pure regions (concentration of magnetic impurities...
A novel form of ball-like carbon material with its size in micrometer range was prepared from coal with nickel as catalyst by arc plasma method. The carbon material has been systematically studied by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and ultraviolet laser Raman spectroscopy. The SEM observation shows that the novel carbon material exists...
Different fluorination methods were applied to modify the surface properties of carbon fibers. The relationship between the degree of fluorination and the physicochemical properties of carbon fibers was studied using a combination of mechanical tests, elemental analysis (EA), X-ray photoelectron spectrometry (XPS), and X-ray diffraction (XRD). EA and XPS analyses of fluorinated carbon fibers showed...
Carbon nanotubes prepared by a classical CVD method with a nickel catalyst have been characterized, then used as conducting anisometric objects dispersed into a polymeric matrix. In a first part, these nanotubes are structurally characterized before and after heat treatments (HTT=1500, 2000, 2500 o C). Diffusion Raman experiments and diamagnetic susceptibility experiments demonstrated their...
The kinetics of carbon deposition from methane were studied over broad ranges of pressures, temperatures and reciprocal surface area/volume ratios. Based on these results, it was possible to distinguish between a growth and a nucleation mechanism of carbon deposition and to select conditions for the preparation of well-defined samples for texture analysis by transmission electron microscopy and selected...
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