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A method to form self-aligned carbon nanotube (CNT) vias using a Ta-cap layer on a Co catalyst by chemical vapor deposition at 400°C is described. The Ta-cap layer protects the Co catalyst from oxidation. This protection potentially eliminated the need for additional processing steps to control the size and activity of the Co catalyst, which are two critical parameters for CNT formation. The Ta-cap...
We report on the manufacturing of ultra-low density carbon foam produced by pulsed laser deposition. Mean mass density, morphology and structure were investigated within a broad range of process parameters. We have been able to obtain carbon foam layers having tunable mean density and thickness in the range 1–1000mg/cm 3 and 5–80 μm, respectively. Surface uniformity has been achieved over...
The fabrication and functionality of a 21cm graphene-based transverse electron emission display panel is presented. A screen-printed triode edge electron emission geometry has been developed based on chemical vapor deposited (CVD) graphene supported on vertically aligned carbon nanotubes (CNT) necessary to minimize electrostatic shielding induced by the proximal bulk substrate. Integrated ZnO tetrapod...
In this paper, we show that the efficiency in the growth of carbon nanocoils is significantly improved by introducing a SnO 2 buffer layer. Carbon nanocoils were synthesized by chemical vapor deposition using an Fe–Mg–Co or Fe–Mg–Co–Sn catalyst supported on an Al 2 O 3 substrate coated with a 30nm SnO 2 buffer layer. The carbon nanocoil growth rate improved by more...
We presented a molecular-designed multi-walled carbon nanotube (MWCNT) layer-by-layer (LbL) multilayer on poly-l-lactic acid (PLLA) electrospun fibers for engineering cell/CNT interfaces. A stable, positively charged monolayer was created on the fiber surface by the aminolysis reaction of poly(ethylene imine) (PEI) with PLLA, followed by alternate deposition in negatively charged MWCNT and positively...
The structural and microstructural changes in graphite occurring by heating a mixture of synthetic polycrystalline graphite and lithium chloride to 1250°C are studied by thermal analysis, X-ray diffraction, Raman scattering and microscopy. The average crystallite size of the graphite was found to increase significantly after the heat treatment. Although the oxidation of graphite was largely inhibited,...
Double-walled carbon nanotubes (DWCNTs) were synthesized by a metal-catalyst-free chemical vapor deposition method using silicon oxide nanoparticles as a catalyst. The diameters and lengths of the DWCNTs are in the ranges of 3–5nm and 1–5μm, respectively. The amount of DWCNTs produced is about 70%, while the remainder is single-walled carbon nanotubes. A heat treatment of the SiO 2 /Si substrate...
The fundamental electrochemical performances of a new carbon called “ICOKE” which was prepared by the graphitization of coke at ca. 2000°C were recently reported. It showed the excellent pulse charge/discharge characteristics and long cycle performance. In the present study, the in-plane structure of Li-intercalated ICOKE was investigated in detail by means of cyclic voltammetry, X-ray diffraction...
Vertical few-layer graphene (FLG) sheets have potential applications as field emitters and super capacitors. However, it remains a challenge to controllably grow FLG with vertical and parallel orientations. We intentionally designed the substrate surface structure to manipulate the distribution of the plasma sheath and induce the direction of the built-in electric field to guide the growth direction...
Graphene oxide (GO) was modified with polyethylene glycol mono-methyl ether 750 (MPEG750) by esterification to increase its dispersibility in solvents and a GO/PEG-4000 composite was prepared by solution blending. Results showed that the GO-MPEG750 is dispersible in both polar and nonpolar solvents. The thermal stability of the PEG-4000 could be improved significantly by adding as little as 1mass%...
A simple method to prepare nitrogen-doped graphene (NG) by a pressure-promoted process at relatively low temperatures is demonstrated. The NG with an atomic N content higher than 10% can be obtained by heating graphene oxide and NH 4 HCO 3 in a sealed autoclave at a temperature as low as 150°C. The product exhibits a specific capacitance of 170Fg −1 at 0.5Ag −1 in 5M...
The formation of a carbon coating on carbon nanotubes (CNTs) was observed in X-ray microscopy experiments. X-ray absorption near-edge structure (XANES) spectroscopy showed that the coating originated from the lacey carbon on the substrate, which was heated by the X-ray beam and then deposited on CNTs. The coating shows some fingerprint features around the π* peak of the C 1s XANES spectrum, which...
Multiwalled carbon nanotubes (MWCNTs) were oxidized by concentrate HNO 3 and then reacted with SOCl 2 to form MWCNT-COCl. Water-soluble sodium p-aminobenzenesulfonate-grafted multiwalled carbon nanotubes (MWCNT-CO-NHC 6 H 5 SO 3 Na) were synthesized by an amidation reaction of sodium p-aminobenzenesulfonate with MWCNT-COCl, which was verified by FT-IR spectroscopy...
Branched CNTs with nitrogen doped/un-doped intratubular junctions have been synthesized by a simple one-step co-pyrolysis of hexamethylenetetramine and benzene. The difference in the vapor pressure and the insolubility of the precursors are the keys for the formation of the branched intratubular junctions. The junctions behave like Schottky diodes with nitrogen-doped portion as metal and un-doped...
A 150μm thick SiC coating was ground to form V-shaped and U-shaped grooves with a 10μm depth, which was followed by partial chlorination to convert the coating to a carbide-derived carbon (CDC) coating. The effect of the grooves in the CDC coating on its tribological properties was investigated. The grooves were removed by further grinding for comparison. It was found that the grooved CDC coating...
Three dimensional (3D) reduced graphene oxide (RGO)-based hydrogels were synthesized by the reduction of graphene oxide using sodium ascorbate. During gelation, mono-, bi-, and trilayer graphene nanosheets self-assemble into a well-defined and interconnected 3D porous network through strong van der Waals and π–π interactions. The 3D RGO-based hydrogels showed a large surface area, and a uniform pore...
Nitrogen-rich carbon precursors are prepared and subsequently used for the preparation of N-doped porous carbons (NPCs). Two carbon precursors (CPs), CP-60 and CP-40, are prepared at different temperatures, 60°C and 40°C, respectively. The obtained CP materials are almost nonporous based on the N 2 adsorption/desorption analysis. These nonporous CP materials are converted into NPC materials...
Magnesium (Mg) and carbon (C) compounds were synthesized by ball-milling a mixture of Mg and different graphites with different crystallinities. The materials were characterized by X-ray diffraction, X-ray absorption spectroscopy, and X-ray total scattering techniques. Hydrogen storage properties were also investigated. In the case of the material using low-crystalline graphite, a Mg and C compound...
Multi-walled carbon nanotube (MWCNT)/portland cement(PC) composites have been fabricated to evaluate their electromagnetic interference (EMI) shielding effectiveness (SE). The results show that they can be used for the shielding of EMI in the microwave range. The incorporation of 15wt.% MWCNTs in the PC matrix produces a SE more than 27dB in X-band (8.2–12.4GHz), and this SE is found to be dominated...
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