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A novel structure of carbon nanonodules containing fewer than 10 layers graphene has grown on amorphous carbon nanofibers by carbonization-induced self-assembly. It is found that a successive processes containing pre-oxidation in air at 220°C and carbonization in a high vacuum (1×10 −4 Pa) at 750°C are necessary for the fabrication of the carbon nanonodules. Possible mechanism for the evolution...
The electrical resistance of polystyrene sheets containing carbon nanotubes (CNTs) and graphene nanosheets (GNSs) was examined as a function of electric field intensity and annealing temperature. The time needed for the percolation threshold to be reached, decreases with increasing field intensity, annealing temperature and filler loading. However, conductive networks were always formed more easily...
Atomic layer deposition (ALD) was used to synthesize metal oxide-carbon nanotube (MO-CNT) hybrid materials by coating nitrogen-doped CNTs (N-CNTs). SnO 2 -CNT hybrids were produced using SnCl 4 and water as precursors and exhibited many unique features. It was demonstrated that the use of N-CNTs was beneficial for directly initiating the ALD of SnO 2 (ALD-SnO 2 ) and...
In this study 2-amino-4,6-didodecylamino-1,3,5-triazine (ADDT) was synthesized from cyanuric chloride and covalently functionalized onto graphene oxide nanosheets. The chemical structure of the alkylated melamine and the functionalized graphene oxide (GO) nanosheets were characterized with 1 H NMR, FT-IR, XPS, TGA and TEM. The results indicate that two chlorine atoms on the triazine ring of...
Natural sepiolite mineral was used as a catalyst and catalyst support for the efficient growth of single-walled carbon nanotubes (SWCNTs). With the introduction of hydrogen, uniform active metal nanoparticles can be formed in the fibrous structure of sepiolite ore. High-quality SWCNTs with few defects and a large aspect ratio (over 10 4 ) were synthesized. The structure of the CNTs was modified...
The transportation of copper atoms along a carbon nanotube (CNT) channel, which consists of a junction, is studied using molecular dynamics simulations. A bias voltage is applied along the channel to induce an electromigration force on copper atoms. The study focuses on the flow of copper atoms by varying the voltage gradient and the temperature of copper. The results show that the temperature increase...
Carbon foams were prepared from mesophase pitch using foaming, carbonization and graphitization processes. The physical and chemical properties of the mesophase pitch during thermal treatment were studied by Fourier transform infrared spectroscopy, thermogravimetry, mass spectroscopy, rheometry and scanning electron microscopy. The results suggest that gases released from the pitch dissolve, saturate,...
A method of carbon nanotubes (CNTs) oxidation at room temperature using ozone with added water vapor is described. The resulting CNTs were characterized by Fourier transform infrared, X-ray photoelectron spectroscopy, and scanning and transmission electron microscopy. These show that more oxygenated functional groups could be grafted onto the CNT surfaces due to the addition of water vapor, compared...
The effect of growth conditions and catalyst lifetime on the supergrowth of carbon nanotubes (CNTs) through a water assisted chemical vapor deposition has been investigated. The reasons behind the observed sudden termination of the CNT growth were explored. A proper amount of water was found to improve the activity of the catalyst and enhance the growth rate of CNTs. However, the introduction of water...
The influence of low cost, commercially oxidized carbon nanofibers (ox-CNFs) on the morphological, thermal, mechanical and electrical properties of polycarbonate (PC) composites was examined. Using a simple solution mixing process leads to good dispersion and high packing density of CNFs in the resultant composites. The composite materials exhibit a dramatic improvement in the DC conductivity; for...
Four different methods, acid oxidation, mechanochemical reaction, ball milling, and grafting following acid oxidation, were used to treat multi-walled carbon nanotubes (MWCNTs). During treatment, hydroxyl groups, carboxylic groups, and amidocyanogen were introduced onto the surfaces of the MWCNTs. The MWCNTs were dispersed into palmitic acid (PA) to prepare phase change composites with high thermal...
High-quality double-walled carbon nanotubes (DWCNTs) thin-films have been fabricated in one-step by the catalytic chemical vapor deposition gas-flow reaction process with acetone as a carbon source in an argon flow. The DWCNTs film is formed through the self-assembly of the DWCNTs in the gas flow, which is achieved by controlling the gas rates in the synthesis reaction. The DWCNT film is self-supported...
A method for the bulk growth of mono- to few-layer graphene on nickel particles by chemical vapor deposition from methane at atmospheric pressure is described. A graphene yield of about 2.5% of the weight of nickel particles used was achieved in a growth time of 5min. Scanning and transmission electron microscopy, Raman spectroscopy, thermogravimetry, and electrical conductivity measurements reveal...
By acetylene decomposition at 450°C over the Fe–Cu nanoparticles (Fe:Cu molar ratio=29:1, 5:1) derived from a combined sol–gel/reduction method, carbon nanobelts (CNBs) and carbon/Fe–Cu hybrid nanoparticles (CNPs) were synthesized simultaneously with high yield. The two carbon species could be easily separated according to color and were collected at different locations of the ceramic plates where...
A graphite electrode was activated using recurrent electrochemical galvanic pulses. After activation, the original smooth surface was changed into an obviously porous, rough surface with microcrystalline flake structures with a larger number of O-containing functional groups. The material had a high capacitance and a satisfactory high-rate performance. The superior volumetric capacitance in active...
Ultra-large mesoporous carbon materials were synthesized with the use of triblock copolymers and phloroglucinol/formaldehyde polymer as filler under acid conditions. The carbons obtained by employing F127 as template and carbonizing at 600°C exhibit large mesopores with a narrow pore-size distribution centered at 19.2nm. With the assistance of decane as a swelling agent, the pore size of the P123-templated...
Carbon nanotube (CNT) yarn was drawn directly from super aligned CNT arrays synthesized by an improved floating catalyst chemical vapor deposition method. The synthesis of aligned CNT was performed as a multi-step interim reactant supply reaction to produce a double-layered CNT array in a horizontal quartz tube reactor. During the growth period, most impurities were blocked on the top surface of the...
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