Microstructure and thermophysical properties of graphite foam/Sn-Bi alloy composites for use as a thermal sink for electronics
Publication date: August 2018Source: New Carbon Materials, Volume 33, Issue 4Author(s): Peng-fei Lian, Jin-liang Song, Shi-wen Lei, Ze-chao Tao, Hong-chao Zhao, Jun-peng Zhang, Zhan-jun LiuAbstractTwo mesophase pitch-based graphite foams with densities of 0.62±0.01 (GF1) and 0.84±0.01 g/cm3 (GF2) were prepared by foaming the pitch in an autoclave at 723 K, 6.0 MPa and 763 K, 13.4 MPa, respectively, followed by carbonization at 1273 K for 2 h and graphitization at 2973 K for 0.5 h. The GFs were infiltrated by a Sn-Bi liquid to prepare GF/Sn-Bi alloy composites for use as thermal sinks for electronics. The microstructures ...
Source: New Carbon Materials - October 5, 2018 Category: Chemistry Source Type: research
Numerical simulation of carrier gas effects on flow field, species concentration and deposition rate in the chemical vapor deposition of carbon
Publication date: August 2018Source: New Carbon Materials, Volume 33, Issue 4Author(s): Teng Yin, Bing-yan Jiang, Zhe-an Su, Zhe-qiong Fan, Qi-zhong HuangAbstractA 2D numerical model was established for simulating the chemical vapor deposition (CVD) of carbon in a vertical reactor. A full multi-component diffusion model was proposed to describe the diffusion of the gas species. The effects of Ar, N2or H2 carrier gases on the flow field, species concentration and deposition rate of pyrocarbon were investigated using C3H6 as the carbon source. Results show that H2 improves the stability of the gas flow. The concentration dis...
Source: New Carbon Materials - October 5, 2018 Category: Chemistry Source Type: research
Electroless Ag deposition on the cell walls of carbon foam by a displacement method
Publication date: August 2018Source: New Carbon Materials, Volume 33, Issue 4Author(s): Cong-cong Guo, Xiu-jun Liu, Tong-qi Li, Yan Lei, Li-li ZhaiAbstractTo obtain efficient metalization of the surface and cell walls of carbon foam, an electroless silver displacement deposition method was investigated, in which a copper layer was first electroless-deposited and then displaced by silver. The purity of the silver coating, and the morphology, microstructure, mechanical strength and electrical conductivity of the resulting carbon foams were characterized by SEM, EDS, XRD, mechanical and conductivity tests. Results indicate th...
Source: New Carbon Materials - October 5, 2018 Category: Chemistry Source Type: research
Preparation of high-carbon-yield pitches from 1-methylnaphthalene through I2O5-assisted electrophilic iodination
Publication date: June 2018Source: New Carbon Materials, Volume 33, Issue 3Author(s): Hai-xiao Yang, He-xiang Han, Ji-tong Wang, Wen-ming Qiao, Li-cheng LingAbstractNovel high-carbon-yield pitches were prepared through the iodination of 1-methylnaphthalene (1-MNP) followed by dehydroiodination/polycondensation. 1-MNP was first iodinated by I2 with the aid of I2O5, yielding mainly 1-iodo-4-MNP. Then, a thermal-dehydroiodination reaction at a comparatively low temperature of 130–180 oC was carried out to condense the iodinated products to obtain the pitches. The structures of the iodinated products and pitches were investi...
Source: New Carbon Materials - July 25, 2018 Category: Chemistry Source Type: research
Molecular dynamics simulation of the thermal conductivity of graphitized graphene/polyimide films
Publication date: June 2018Source: New Carbon Materials, Volume 33, Issue 3Author(s): Jing-cheng Xu, Si-chang Dai, Hao-liang Li, Jun-he YangAbstractGraphitized polyimide strips act as bridges between graphene nanoribbons to form macro-scale graphitized graphene/polyimide films. The effect of the sizes of the two components was investigated by non-equilibrium molecular dynamics simulation using the optimized Tersoff molecular force field. Results indicate that the thermal conductivity of the graphene nanoribbon increases almost linearly with length for lengths below 800 nm, but increases as a power function and converges to...
Source: New Carbon Materials - July 25, 2018 Category: Chemistry Source Type: research
Hydrolysis and carbonization mechanism of cotton fibers in subcritical water
Publication date: June 2018Source: New Carbon Materials, Volume 33, Issue 3Author(s): Li-ping Cui, Sheng Shi, Wen-sheng Hou, Zhi-feng Yan, Jin-ming DanAbstractWaste cotton fibers were used as the raw material to prepare carbon microspheres by treatment with subcritical water. Results show that the cotton fibers are hydrolyzed, dehydrated and carbonized to form carbon spheres with a graphitic structure in subcritical water with different pH values. The carbon spheres prepared at a pH value of 3.5 have particle sizes of 0.8–3 μm and a carbon content of 74.99%. High temperature and pressure lead to the destruction of the c...
Source: New Carbon Materials - July 25, 2018 Category: Chemistry Source Type: research
Large-surface-area carbons derived from lotus stem waste for efficient CO2 capture
Publication date: June 2018Source: New Carbon Materials, Volume 33, Issue 3Author(s): Xing-xing Wu, Cheng-yun Zhang, Zhong-wei Tian, Jin-jun CaiAbstractPorous carbons with a large number of micropores were obtained by the hydrothermal carbonization of lotus stems followed by KOH activation, and their CO2 capture performance was evaluated. The influence of KOH/char ratio on the pore texture and surface chemistry of the carbons was investigated by N2 adsorption, SEM, TEM and elemental analysis. Results indicate that as-prepared carbons had surface areas up to 2893 m2/g and pore volumes up to 1.59 cm3/g, and that KOH activati...
Source: New Carbon Materials - July 25, 2018 Category: Chemistry Source Type: research
Rapid and green synthesis of fluorescent carbon dots from starch for white light-emitting diodes
Publication date: June 2018Source: New Carbon Materials, Volume 33, Issue 3Author(s): Jing-xia Zheng, Xing-hua Liu, Yong-zhen Yang, Xu-guang Liu, Bing-she XuAbstractA simple and green synthesis of fluorescent carbon dots (CDs) was achieved by a microwave-assisted hydrothermal method using potato starch as the carbon source. CDs with a maximum quantum yield of 2.46% were prepared by hydrothermal treatment of a 1 mg/mL starch solution at 220 oC for 30 min. Nitrogen doped CDs (N-CDs) were obtained under the same conditions using starch and ethylenediamine as the carbon and nitrogen sources, respectively, and their quantum yie...
Source: New Carbon Materials - July 25, 2018 Category: Chemistry Source Type: research
Carbon-supported metal single atom catalysts
Publication date: February 2018Source: New Carbon Materials, Volume 33, Issue 1Author(s): Hai Li, Hai-xia Zhang, Xiao-li Yan, Bing-she Xu, Jun-jie GuoAbstractMetal single atom catalysts (SACs) have been attracting increasing attention in recent years owing to their incredible performance in several key catalytic reactions such as the oxygen reduction reaction and CO oxidation. The construction of well dispersed stable SACs can not only make it possible to understand the catalytic reactions on the atomic scale, but is also important for developing novel industrial catalysts. Recent efforts have been focused on dispersing me...
Source: New Carbon Materials - July 11, 2018 Category: Chemistry Source Type: research
Stabilizing graphene layers by intercalating laponite between them
Publication date: February 2018Source: New Carbon Materials, Volume 33, Issue 1Author(s): Jing Li, Jin-can Cui, Zhen-zhen Yang, Han-xun Qiu, Zhi-hong Tang, Jun-he YangAbstractThe reduction of graphene oxide (GO) leads to the re-stacking/agglomeration of graphene layers, which results in their precipitation from an aqueous dispersion. A laponite colloid was used to prevent re-stacking and stabilize an aqueous dispersion of reduced graphene oxide (RGO) by dispersing GO in the colloid, followed by reduction with hydrazine hydrate under microwave radiation. Results indicate that re-stacking is prevented as proven by the disapp...
Source: New Carbon Materials - July 11, 2018 Category: Chemistry Source Type: research
Synthesis of copper sulfide/reduced graphene oxide nanocomposites for use as the counter electrodes of high-performance CdS-sensitized solar cells
Publication date: February 2018Source: New Carbon Materials, Volume 33, Issue 1Author(s): Amr Hessein, Ahmed Abd El-MoneimAbstractCopper sulfide (CuxS)/reduced graphene oxide (RGO) nanocomposites were prepared by a one-pot hydrothermal method with various contents of GO in the initial precursor. The nanocomposites were first blended with a polyvinylidene fluoride binder, then coated onto SnO2−xFx substrates, which were used as the counter electrodes (CEs) of quantum dot solar cells (QDSCs) using a CdS-sensitized TiO2 as a photoanode. The microstructure and performance of the CEs were characterized by FE-SEM, XRD, Raman s...
Source: New Carbon Materials - July 11, 2018 Category: Chemistry Source Type: research
The cytotoxicity of water-soluble carbon nanotubes on human embryonic kidney and liver cancer cells
Publication date: February 2018Source: New Carbon Materials, Volume 33, Issue 1Author(s): Shi-ping Yu, Xu-dong Su, Jing-lei Du, Jun-li Wang, Yu-duan Gao, Li Zhang, Lin Chen, Yong-zhen Yang, Xu-guang LiuAbstractThe cytotoxicity of polyethylene glycol-modified carbon nanotubes (PEG-CNTs) on human embryonic kidney cells (293T) and hepatoma cells (HepG2) was studied in vitro. The effect of the concentration of PEG-CNTs on the cell activity and survival rate was detected by a colorimetric assay method after exposure for 24, 48 and 72 h. The dead HepG2 cells obtained by incubation in solutions with different concentrations of PE...
Source: New Carbon Materials - July 11, 2018 Category: Chemistry Source Type: research
Specific heat capacities and flow resistance of an activated carbon with adsorbed helium as a regenerator material in refrigerators
Publication date: February 2018Source: New Carbon Materials, Volume 33, Issue 1Author(s): Liu-biao Chen, Chun-hui Kong, Xian-lin Wu, Yuan Zhou, Jun-jie WangAbstractAn ideal regenerator material is characterized by a high specific heat capacity and a low flow resistance, and the specific heat capacity of the working gas must be low. However, the specific heat capacity of a helium working gas is much higher than that of the general regenerator materials in the temperature range 4-30 K, which severely limits the improvement of the refrigerator performance. The helium adsorption capacity of the activated carbon was first evalu...
Source: New Carbon Materials - July 11, 2018 Category: Chemistry Source Type: research
Preparation and characterization of high softening point and homogeneous isotropic pitches produced from distilled ethylene tar by a novel bromination method
Publication date: February 2018Source: New Carbon Materials, Volume 33, Issue 1Author(s): Chuan-zhang Ge, Zhen-long Sun, Hai-xiao Yang, Dong-hui Long, Wen-ming Qiao, Li-cheng LingAbstractHomogeneous isotropic pitches with high softening points were prepared from vacuum-distilled heavy residue ethylene tar (ET-HR) by a two-step method of bromination and subsequent dehydrobromination/polycondensation. The ET-HR was first brominated at 30 or 200 oC, and then heat-treated at 350 oC to enable the dehydrobromination/polycondensation reactions. GC/MS and LDI TOF/MS spectra indicated that the ET-HR was mainly composed of compounds...
Source: New Carbon Materials - July 11, 2018 Category: Chemistry Source Type: research
Carbon materials in a high temperature gas-cooled reactor pebble-bed module
Publication date: April 2018Source: New Carbon Materials, Volume 33, Issue 2Author(s): Xiang-wen Zhou, Yang Yang, Jing Song, Zhen-ming Lu, Jie Zhang, Bing Liu, Ya-ping TangAbstractCompared with the long use of carbon materials in human history, the debut of carbon materials in the Chicago Pile-1 nuclear reactor took place only 70 years ago. Since then, carbon materials have played important roles in nuclear reactors, especially in high temperature gas-cooled reactors (HTRs) because of their many excellent properties. As the most promising candidate for Generation IV reactors, a demonstration plant for HTRs, an HTR pebble-b...
Source: New Carbon Materials - July 11, 2018 Category: Chemistry Source Type: research
