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Monolithic porous carbon (MPC) was synthesized by a templating method using Na 2 CO 3 as template, novolac-type phenolic resin as carbon precursor and hexamethylenetetramine as hardening agent. The template, carbon precursor and hardening agent were mechanically mixed in a grinding machine, hardened at 150°C, crushed into fine particles, compacted into a disc, carbonized at 800°C and...
The SiC f /SiC composites containing various thickness of pyrolytic carbon (PyC) interphase were prepared and their properties were investigated for electromagnetic interference (EMI) shielding applications in the frequency of 8.2–12.4GHz. The composites containing 310nm thickness (3.3vol%) PyC interphase show an about 25dB shielding effectiveness in the whole frequency band. Interestingly,...
Dechlorination by oxidative coupling during the adsorption of mono-chlorophenols (mono-CPs) onto activated carbon (AC) was investigated, and the effects of various parameters such as amount of dissolved oxygen, surface structure and temperature of solution on dechlorination amount were examined. Under anoxic conditions, the amounts of adsorption and dechlorination for mono-CPs decreased compared to...
Nitrogen-doped mesoporous carbons (NMCs) with ordered to disordered pore structures were fabricated on SBA-15 modified with different concentrations of tetraethyl orthosilicate using pyrrole as a carbon source. The carbonization temperature of NMCs was maintained at 800°C so that the amount and type of nitrogen functionalities were constant. Pt nanoparticles (NPs) were deposited onto NMCs using a...
Spatial distribution of nitrogen functional groups on graphene by use of physical masks during plasma processing is demonstrated. Structural and chemical modifications are evidenced by micro-Raman and high-resolution X-ray photoelectron spectroscopy mapping, demonstrating a strong dependence on the processing conditions and physical mask configurations. The resulting nitrogen chemical moieties influence...
The current study uses nuclear magnetic resonance, Fourier-transform infrared spectroscopy and Raman spectroscopy to investigate the evolution of refined softwood and hardwood lignins under various pyrolytic exposures. Little chemical change occurred at pyrolysis temperatures of 250 and 300°C, whereas significant mass loss and chemical change was observed at 400 and 500°C. These losses were mainly...
A graphitic mesoporous carbon was prepared using sucrose as carbon precursor and Ni–Fe (Ni/Fe=2) double-layered hydroxide (DLH) as template and catalyst precursor by a solid-phase method. The material was characterized by X-ray diffraction, Raman spectroscopy and high-resolution transmission electron microscopy. Results indicated that the graphitic mesoporous carbon has a uniform mesopore size and...
The effect of dispersion state of graphene on mechanical properties of graphene/epoxy composites was investigated. The graphene sheets were exfoliated from graphite oxide (GO) via thermal reduction (thermally reduced GO, RGO). Different dispersions of RGO sheets were prepared with and without ball mill mixing. It was found that the composites with highly dispersed RGO showed higher glass transition...
We prepared flexible, lightweight, and high electromagnetic interference (EMI) shielding performance graphene nanosheet (GNS)/water-borne polyurethane (WPU) composites. WPU, with sulfonate functional groups, was used as the polymer matrix. By adsorbing the cationic surfactant (stearyl trimethyl ammonium chloride) on the surface of the GNSs (S-GNSs), restacking and aggregation of the GNSs have been...
The synthesis of NiO/C nanocapsules with NiO nanoparticles as the core and onion-like carbon layers as the shell is reported. The NiO/C nanocapsules deliver an initial discharge capacity of 1689.4mAhg −1 at 0.5 C and maintain a high reversible capacity of 1157.7mAhg −1 after 50cycles compared to the NiO nanoparticles of 383.5mAhg −1 . As an anode material for lithium ion batteries,...
A rapid reforming of natural honey exposed to reactive low-temperature Ar+H 2 plasmas produced high-quality, ultra-thin vertical graphenes, without any metal catalyst or external heating. This transformation is only possible in the plasma and fails in similar thermal processes. The process is energy-efficient, environmentally benign, and is much cheaper than common synthesis methods based...
Water-soluble hydroxylated multi-wall carbon nanotubes (MWCNTols) were synthesized by the NaOH/H 2 O 2 oxidation method. A L 9 (3 4 ) orthogonal experimental design was used to optimize the preparation conditions, and TEM, SEM and Raman spectroscopy were used to characterize the products. The solubility of as-prepared MWCNTols in water was 0.72mg/mL. Furthermore, MWCNTols...
Graphene oxide–Fe 2 O 3 (GO–Fe 2 O 3 ) hybrid material was synthesized as a heterogeneous catalyst for photo-Fenton degradation of organic contaminants by an easy and scalable impregnation. X-ray diffraction analysis and high-resolution transmission electron microscope analysis confirm the existence of the Fe 2 O 3 nanoparticles in the GO–Fe 2 ...
Nano graphene oxide (NGO) was produced by further refluxing graphene oxide (GO) sheets in HNO 3 , and carboxylic acid functionalized graphene oxide (GO–COOH) was obtained by a simple etherification reaction between GO and chloroacetic acid. The GO, GO–COOH and NGO sheets are combined with TiO 2 nanorods by a two-phase assembling method, and confirmed by transmission electronic microscopy...
We synthesized highly porous composite films of vertically aligned carbon nanotubes (CNTs) and polypyrrole (PPy) by employing a simple in situ electropolymerisation process from aqueous pyrrole solutions. By contacting the entire CNT array, each CNT acts as a highly active anode that facilitates uniform deposition and immediate polymerization of pyrrole directly on the CNT surface. As a result, each...
Surface compression is a phenomenon in which strong solid–fluid interactions compress the adsorbate molecules on a surface to a point that lateral repulsion forces appear. In this work, this phenomenon was studied for high pressure adsorption of a collection of light gases on polyfurfuryl alcohol (PFA)-derived carbons. The carbons were mostly microporous with mean pore sizes ranging from 5 to 8Å....
Electrochemical behavior of the polyacrylonitrile (PAN)-based graphite as a low cost electrode material for vanadium based redox batteries (VFB) in sulfuric acid medium has been improved by means of the successful introduction of nitrogen and oxygen-containing groups at the graphite surface by thermal activation under NH 3 /O 2 (1:1) atmosphere. Influence of the temperature and treatment...
Activated carbon (AC) was modified with sodium citrate at a concentration of 5–15% by impregnation to develop a new type of adsorbent, named N x –AC where x is the concentration. Their pore structures and surface chemical properties were characterized by N 2 adsorption, Boehm titration and FT-IR. The adsorption of copper ions by the N x –AC and the regenerated ones were investigated...
Defective graphene nanosheets (GNSs), single-walled carbon nanotubes (SWCNTs), and herringbone graphite nanofibres (GNFs) were used as Pd 3 Pt 1 catalyst supports for an oxygen reduction reaction (ORR). Raman spectroscopy and cyclic voltammetry analyses revealed oxygen-containing functional groups and physical defects on the surfaces of the SWCNTs, GNFs, and synthesised GNSs. Mass-transfer-corrected...
This paper aimed to study the fracture behavior of nuclear graphite NBG-18 through three-point bend tests with single-edge-notched beams. The size effect on its fracture toughness and associated statistical characteristics was studied by using three different specimen sizes: (I) 200mm(Span)×50mm(Width)×25mm(Thickness), (II) 100mm(S)×20mm(W)×10mm(T) and (III) 40mm(S)×10mm(W)×5mm(T). Digital image correlation...
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