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We demonstrate a direct and stable aerosol synthesis of single-walled carbon nanotubes (SWCNTs) using a hot wire generator (HWG) method, with iron physically evaporated in a carbon monoxide (CO) atmosphere as the catalyst source. A small amount of added carbon dioxide increased the lifetime of the Fe wire in reacting CO up to several weeks. This approach allowed us to significantly increase the yield...
Nitrogen-doped graphene–silver nanoparticle hybrids were prepared by thermal treatment of graphite oxide (GO) with glycine and silver nitrate at 500°C. Glycine was used to reduce the nitrate ions, resulting in the decomposition of a glycine–nitrate mixture near 200°C. The products of decomposition act as sources for nitrogen doping. The thermal treatment of a mixture of GO, glycine and silver nitrate...
Ordered mesoporous silica/carbon composite membranes with a high CO 2 permeability and selectivity were designed and prepared by incorporating SBA-15 or MCM-48 particles into polymeric precursors followed by heat treatment. The as-made composite membranes were characterized by high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and N 2 adsorption, of which...
We reveal that the collective growth of vertically aligned carbon nanotube (CNT) forests by chemical vapor deposition (CVD) is governed by the size-dependent catalytic behavior of metal nanoparticles, which can be quantitatively related to the activation and deactivation kinetics of subpopulations of CNTs within the forest. We establish this understanding by uniquely combining real-time forest height...
Carbon nanofibers (CNFs) were fabricated by thermal treatment of electrospun nanofibers obtained from precursor blends of polybenzimidazole (PBI) and Matrimid®. The microcarbon structures of CNFs obtained from PBI, and the 50:50 and 75:25 blends were studied using XRD and Raman spectra. Nitrogen adsorption/desorption measurements revealed that surface area and porosity of CNFs increased with an increase...
A flexible electrode was prepared by microwave heating deposition of manganese oxide (MnO 2 ) on carbon nanotubes (CNTs) followed by electrophoretic deposition of the MnO 2 -coated CNTs on a flexible graphite sheet (FGS). The prepared MnO 2 -coated CNTs were characterized by scanning and transmission electron microscopy, and X-ray diffraction. A uniformly thin nano-scale MnO...
The porosity of a typical activated carbon is investigated with small angle neutron scattering (SANS), using the contrast matching technique, by changing the hydrogen/deuterium content of the absorbed liquid (toluene) to extract the carbon density at different scattering vector (Q) values and by measuring the p/p 0 dependence of the SANS, using fully deuterated toluene. The contrast matching...
Hybrid structures combining fullerenes and carbon nanotubes have exhibited exciting properties. However, the low efficiency and complex process of such assembly restrict their practical applications. We report a single-step procedure to synthesize the fullerene-intercalated (including endohedral metallofullerene (Y@Cn)) porous carbon nanofibers (pCNFs) by chemical vapor deposition (CVD) using a Fe/Y...
We reported the fabrication of a hierarchical carbon nanotube (CNT) membrane by using the 90% granulated double- or triple-walled CNTs and 10% 100μm long multiwalled CNTs as the linker. The membrane with packing density of 420kg/m 3 , excellent electrical conductance and good mechanical strength, functioned as both the electrode and current collector and allowed the weight ratio of CNTs increased...
An examination of the peculiarities of ρ-electron conjugation of carbon atoms in spherical (fullerenes) and cylindrical (single-walled carbon nanotubes) molecular systems was performed using an analysis of topological isomerism of [N]-annulenes. It was demonstrated that a ρ-electron conjugation has a stabilizing effect with respect to a π-electron conjugation; however, the value of this effect is...
We compare deformation behavior of conventional carbon and carbon-nanotube (CNT) based aerogels with monolith densities of 30–300mgcm −3 . Results show that CNT-based aerogels have superior elastic moduli, comparable failure stresses, and, hence, lower failure strains. The density scaling law exponents are statistically indistinguishable for both types of aerogels, suggesting the same ligaments...
We report the synthesis of large-area graphene films on Mo foils by chemical vapor deposition. X-ray diffraction indicates that the dissolution and segregation process governs the growth of graphene on Mo foils. Among all processing parameters investigated, the cooling rate is the key one to precisely control the thickness of graphene film. By optimizing the cooling rate between 1.5 and 10°C/s, we...
We have investigated the magnetoresistance (MR) behavior of few-layer graphene grown on copper foils by chemical vapor deposition (CVD). We have found that the graphene consisting of 3–5 layers with fewer defects shows weak localization and positive MR effects, while the positive MR effect disappeared in graphene with higher defect density. The positive MR observed in our graphene samples with fewer...
Two-dimensional dielectric sheets composed of graphene-supported amorphous carbon were prepared by annealing polyaniline-coated graphene oxide sheets in vacuum. The morphology and structure were characterized by scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and Fourier-transform infrared spectroscopy. This showed that annealing the polyaniline-coated graphene oxide had little...
Natural flake graphite/polymer composite sheets were prepared using tape casting method. The in-plane thermal conductivities, i.e. the thermal conductivities along the tape casting plane, of the composites were measured and the results compared to the predictions by the Maxwell and Agari models. The comparison indicated that both models cannot predict the thermal conductivity of the natural flake...
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...
Activated carbons exhibiting high hydrogen electrosorption were produced from selected precursors: coconut shells, blackthorn stones, cellulose and lignin. The influence of the carbonization condition and activation with KOH on their structural parameters and, hence, hydrogen electrosorption ability, was investigated. A positive effect of fast, aggressive activation was demonstrated for precursors...
We report on the exceptional application of polyaniline/graphene composites (PAGCs) for corrosion protection of steel. The composites display outstanding barrier properties against O 2 and H 2 O compared with neat polyaniline and polyaniline/clay composites (PACCs). The conductive filler, 4-aminobenzoyl group-functionalized graphene-like sheets (ABF-G) with a relatively higher aspect...
Thin films of graphite oxide silylated with octyltrichlorosilane were first prepared and they were further silylated with 3-aminopropyltriethoxysilane. Pillared carbon thin films with an interlayer spacing of 1.7nm were prepared from the pyrolysis of the resulting thin films. Larger propylene carbonate molecules were not intercalated into them. They showed selective electrical response to electron...
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