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The carbon materials carbon nanotubes (CNTs), graphite, and activated carbon were tested as metal-free catalysts. They showed excellent activity and selectivity in the Baeyer–Villiger (B–V) oxidation of cyclohexanone at room temperature using dioxygen (O 2 ) as oxidant and benzaldehyde as sacrificial agent. Among them graphite was found to be the most suitable for the formation of lactones...
The effect of adding carbon nanomaterials on the thermal conductivity of liquid paraffin-based suspensions was investigated. These included pristine and carboxyl-functionalized short multi-walled carbon nanotubes (MWCNTs), long MWCNTs, carbon nanofibers, and graphene nanoplatelets (GNPs). The thermal conductivity of the suspensions was measured using the transient hot-wire method at a constant temperature...
We demonstrate a laser-based technique to directly synthesize few layer graphene on quartz substrates without using any metal catalyst. In our approach, a photoresist S-1805 (from Shipley Comp.) film coated on quartz wafers was heated, and then decomposed, by irradiation of a continuous-wave laser. The carbon atoms from the photoresist were dissolved in the molten quartz, and then extracted to form...
A PAN-based carbon fiber paper preform prepared by a dry casting method was impregnated with phenolic resin mixed with graphite powder, which was mold-pressed, cured, carbonized and graphitized to prepare carbon paper for proton-exchange membrane fuel cells (PEMFCs). The effect of graphite powder content on the properties of the carbon paper was investigated. Results showed that the thickness, porosity,...
We experimentally and theoretically investigated the influence of a model drug, doxorubicin (DOX) on GO interlayer interaction by evaluating the pyrolysis activation energy using thermogravimetric analysis and a mathematical model. It was found that the pyrolysis activation energy of DOX-loaded GO decreased from 145.8 to 119.5kJ/mol with DOX loading content increasing from 0 to 186.6w/w%. Theoretical...
Self-organization of nitrogen-doped carbon nanotube (N-CNT) double helices was achieved by chemical vapor deposition (CVD) with Fe–Mg–Al layered double hydroxides (LDHs) as the catalyst precursor. The as-obtained N-CNT double helix exhibited a closely packed nanostructure with a catalyst flake on the tip, which connected the two CNT strands on both sides of the flake. A mechanism for the self-organization...
Graphene–carbon nanotube hybrid materials were successfully prepared through the π–π interaction without using any chemical reagent. We found that the ratio between carbon nanotube and graphene had critical influences on the state in aqueous solution and morphology of hybrid materials. Field emission scanning electron microscope and transmission electron microscope analysis confirmed that graphene...
A series of measurements using a novel technique called electrostatic-manipulation scanning tunneling microscopy were performed on a highly-oriented pyrolytic graphite (HOPG) surface. The electrostatic interaction between the STM tip and the sample can be tuned to produce both reversible and irreversible large-scale vertical movement of the HOPG surface. Under this influence, atomic-resolution STM...
The secondary electron (SE) emission (SEE) in a triode carbon nanotube (CNT) field emission display (FED) and its influence on the image quality have been studied with a 3.5in. vacuum-sealed FED prototype fabricated by using screen printing and frit sealing techniques. By analyzing the emission property difference of the device under two different kinds of work modes, we have found that it is the...
Carbon nanotubes (CNTs) have been deposited onto carbon-fiber fabric using electrophoretic deposition (EPD) prior to the infusion of epoxy resin for the production of carbon/epoxy composites. The carbon-fiber fabric employed for EPD was used in the as-received condition, in which the proprietary epoxy sizing-agent was present. CNTs were functionalized prior to EPD using ozone treatment for oxidation,...
A carbon block with ultra-high anisotropy was produced from a commercial graphite paper as the thermal reinforcement and a thermosetting phenolic resin as the binder. Hot-pressing at a maximum temperature of 200°C was used to densify and integrate the graphite paper stacks. It has been found that the graphite paper blocks have high thermal conductivities in the paper direction and low ones perpendicular...
A method has been developed for synthesizing high-surface-area carbon nanoparticle/graphene composites. Functionalized carbon nanoparticles were anchored to the graphene planes and function as spacers to prevent the restacking of graphene sheets during drying. The composite has a layered structure in which functionalized carbon nanoparticles are sandwiched between graphene stacks. This layering leads...
Using resorcinol and formaldehyde as carbon precursors, graphitic mesoporous carbons (GMC) with different surface areas were synthesized by adjusting the amount of iron nitrate used as a graphitization catalyst. The BET surface area of the GMC decreases with increasing pore diameter and the material becomes more graphitic with increasing amount of catalyst. Using the GMC as the support, a series of...
Vapor grown carbon nanofibers (VGCNFs) were deposited on carbon fibers (CFs) using electrophoretic deposition (EPD). Composites of the resulting hybrid material (CF-VGCNF) in an epoxy matrix were fabricated by the vacuum-assisted resin transfer molding process. The electrical conductivities of the composites were significantly improved compared to those without the VGCNF reinforcement. The Taguchi...
Graphite oxide (GO)/ordered polyaniline (PANI) composites have been prepared through an in situ polymerization. TEM, XRD, FTIR and XPS analyses show that the PANI grew along the surface of exfoliated GO as a template to form a more ordered structure with high crystallinity during polymerization. Compared with pure PANI, both higher electrical conductivity and higher Seebeck coefficient of GO/PANI...
Carbon nanotube (CNT) fluids with liquid-like behavior were synthesized and incorporated into a polymeric matrix to investigate the processability and mechanical performance of the resulting composite, as well as the distribution of CNTs in the host material. We demonstrated that the simultaneous reinforcement and plasticization effect on the polymeric matrix by the novel multifunctional component...
Two-beam-laser interference was used for the simultaneous reduction, patterning and nanostructuring of graphene oxide on flexible polyethylene terephthalate substrates for the production of a high performance humidity sensing device. Hierarchical graphene nanostructures were formed after laser interference treatment of graphene oxide, which holds great promise for gaseous molecular adsorption, and...
Hollow carbon nanospheres (HCNSs) were prepared on large scale by the reaction of AlCl 3 ·6H 2 O and CaC 2 in the temperature range of 250–500°C. Characterization of the products by X-ray diffraction, Raman spectroscopy and transmission electron microscopy indicates that they have a uniform size of about 30nm and a high degree of graphitization. Based on a series of comparative...
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