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The synthesis of platelet carbon nanofibers (PCNFs) on a silicon substrate using chemical vapor deposition method is reported. Scanning electron microscope, high-resolution transmission electron microscopy, and Raman spectroscopy were used to characterize the nanofibers. It is found that these platelet nanofibers are of the order of 10μm long, and most have a nearly rectangular transverse section...
Activated carbon fiber fabrics, an excellent adsorbent, were used as catalyst supports to grow carbon nanofibers. Because of the microporous structure of the activated carbon fibers, the catalysts could be distributed uniformly on the carbon surface. Based on this concept, the carbon nanofibers can be grown directly on the activated carbon fiber fabrics. We demonstrate that carbon nanofibers with...
Single crystal magnesium oxide (MgO) was found to be very beneficial to the growth of aligned carbon nanotube (CNT) arrays as long as 2.2mm by chemical vapor deposition. Before growth, a thin film of catalyst (iron) was coated on the MgO by magnetron sputtering. Scanning electron microscopy was used to study the alignment and length, and transmission electron microscopy was used to exam the wall numbers,...
We have evaluated the biological responses to four different types of carbon nanotubes (CNTs), by measuring CD4 + and CD8 + T-cells in peripheral blood, and by the histopathological study on tissues surrounding subcutaneously implanted CNTs for up to 3 months. All mice survived, and no large changes in their weights were observed within our experimental period. After 1 week, only single-walled...
Because of the unique structural, mechanical, and electrical properties, 1-D (one-dimensional) carbon nanotubes and nanofibers have been studied for possible use in many fields from molecular electronics to biomedical applications for several years. The 1-D carbon nanomaterials are produced presently on large scale. The inhalation of ultrafine nanocarbons can cause inflammatory lung response. The...
The cytotoxicity of different samples of carbon nanotubes synthesised by catalytic chemical vapour deposition was investigated towards human umbilical vein endothelial cells, using two cytotoxicity standard assays (neutral red assay for the cell viability and MTT assay—tetrazolinium salt—for the cell metabolic activity). No cytotoxicity was found for any sample.
A simple and efficient approach for coating multiwalled carbon nanotubes (MWCNTs) with size-controllable SnO 2 nanoparticles by chemical vapor deposition has been developed using tin hydride (SnH 4 ) gas as the source of SnO 2 at 550°C. The size and coverage of SnO 2 nanoparticles can be adjusted by simply controlling the deposition time and the flow rate of the SnH...
The self-assembly of carbon nanotubes (CNTs) on the inside wall of a relatively long stainless steel tubing for applications such as separations and chromatography, is reported in this paper. The CNTs were deposited by the chemical vapor deposition (CVD) using ethylene as the carbon source and the iron nanostructures in the stainless steel as the catalyst. The coating consisted of a layer of CNTs...
Carbon nanotubes (CNTs) were grown using a modified atmospheric pressure plasma with NH 3 (210sccm)/N 2 (100sccm)/C 2 H 2 (150sccm)/He(8slm) at low substrate temperatures (⩽500°C) and their physical and electrical characteristics were investigated as the application to field emission devices. The grown CNTs were multi-wall CNTs (at 450°C, 15–25 layers of carbon sheets,...
Multi-branched carbon nanofibers with a porous structure have been synthesized on a Cu catalyst doped with Li, Na, or K. The products were characterized by field emission scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy and Raman spectroscopy. Using this new type of nanofiber as polarized electrodes, an electrochemical double-layer capacitor...
Carbon nanofibers were produced by the catalytic CVD process by the floating catalyst method, in semi-industrial systems at temperatures above 1350K. Iron-derived carbon nanofibers were produced from natural gas and xylene, using ferrocene as catalyst source, yielding a thickened submicron vapor grown carbon fibers with a core of multi-wall nanotubes. For the production of Ni derived nanofibers, natural...
A simple yet versatile combinatorial method to discover binary metal nanoparticle catalysts was developed. In this method, the nominal thickness of component metals can be independently screened for a wide range by simply setting a mask with a slit above a substrate during sputter-deposition. Using this method, we prepared a catalyst library with Mo (0.2–4nm) and Co (0.2–8nm) thickness profiles on...
The deposition of carbon nanotubes using the laser assisted chemical vapor deposition process was studied to determine the effects of processing conditions on the quantity and quality of the tubes. A structured experimental design was utilized to test the effects of laser power, and concentration of the two precursors, acetylene and iron pentacarbonyl. Processing conditions were optimized with the...
Vapor-grown carbon fibers (VGCFs) with high-purity have been successfully prepared from the thermal cracking of deoiled asphalt (DOA) with ferrocene as catalyst by chemical vapor deposition (CVD) in argon atmosphere and characterized systematically by field-emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) techniques...
The methane conversion and carbon yield of the chemical vapor deposition (CVD) reaction suggests that the optimum reaction conditions of the formation of multi-wall carbon nanotubes (MWCNTs) can be obtained by using a 50mg of nano-MgNi alloy under pyrolysis of the pure CH 4 gas with the flow rate about 100–120cm 3 /min at 650°C for 30min. Raman results indicate the CNTs are in multi-wall...
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