新型炭材料

SHEN Zeng-min, GE Min, ZHAO Dong-lin

2005, 20(04): 289-293.

Abstract(2296)

PDF(2150)

Abstract:
Carbon microcoils with coil diameter about 4μm, pitch about 0.5－0.8μm (A) and coil diameter about 20μm, pitch about 1－4μm (B) were prepared by a vapor phase catalytic cracking process. Paraffin wax/carbon microcoil composites were made by dispersing the latter in the former, which were sandwiched between epoxy glass plates and Nomex honeycomb plates. The complex permittivity (ε) and the complex permeability (μ) of the composites were measured at 8.2－12.4GHz by a reflection transmission system. Results show that the permittivity loss tangent of paraffin wax/B composites is higher than that of paraffin wax/A composites. A-coils show a better microwave absorbing property than B-coils. The microwave reflection loss of the sandwiched composites filled with A-coils is more than 10dB at the range of 10-15GHz, more than 5dB at the range of 4.6-18GHz and the maximum microwave reflection loss is 18dB at a frequency of 12.4GHz, which are opposite to the results expected from the loss tangent (tanδε＝ε″/ε′). It is assumed that A-coils with a smaller diameter and pitch have a higher chiral parameter (ξ) value. Moreover, the value of ξhas a greater impact on the microwave absorption than the εvalue for the carbon microcoils, which results in better microwave absorbing properties.

不同结构活性炭对甲苯的吸附性能(英)

SONG Yan, QIAO Wen-ming, Seong-Ho Yoon, Isao Mochida

2005, 20(04): 294-298.

Abstract(2952)

PDF(2097)

Abstract:
The toluene adsorption behavior of various activated carbons with different surface areas and pore structures was investigated by a static method at saturation concentration and a dynamic method at low concentration. The pore structures of these activated carbons were characterized by nitrogen adsorption at 77K and 129Xe-NMR measurements. Results showed that activated carbons with a larger pore volume have the higher toluene adsorption capacity at saturation concentration. But at low concentration, activated carbons with abundant micropores and a narrow pore size have a higher adsorption capacity. Among the investigated samples, pitch-based activated carbon fibers (ACFs) showed a better toluene adsorption capacity at low concentration (2×10-5). With the increase of surface area for ACFs, the toluene adsorption capacities at low concentration (2×10-5) increase slightly and for OG5A, OG10A, OG15A and OG20A at 30℃ were 202 mg/g, 219 mg/g, 221 mg/g and 235 mg/g respectively.

流延涂布法制备活性炭电极膜片的超级电容器

ZENG Yu-qun, LI Bao-hua, ZHOU Peng-wei, KANG Fei-yu, CHEN Li-quan

2005, 20(04): 299-304.

Abstract(3114)

PDF(2298)

Abstract:
The fabrication of activated carbon laminated stacked supercapacitor electrodes and their electrochemical properties are described. The material cost can be reduced to a commercially acceptable level by using actived carbon. In addition, the introduction of continuous spread technology for preparing activated carbon electrodes provides mass production capability. Supercapacitors with good electrochemical performance were confirmed by experimental charge-discharge with low internal resistance and leakage current. The energy density of the supercapacitors with KOH as electrolyte is 1.16 Wh/Kg and the capacitance decay less than 20% after over 50000 cycles is obtanied under large discharge current condition. They can work at temperatures from －20℃ to 80℃. After 500 days on the shelf, the capacitance remains unchanged.

炭气凝胶及其有机气凝胶前驱体的吸附性能

WU Ding-cai, LIU Xiao-fang, FU Ruo-wen

2005, 20(04): 305-311.

Abstract(2547)

PDF(1839)

Abstract:
Carbon aerogels were prepared by sol-gel polycondensation of resorcinol and furfural in alcohol using hexamethylenetetramine as a catalyst, and then directly drying the organic gels under conventional ambient pressure drying conditions, followed by carbonization under a nitrogen atmosphere. The structures of the organic aerogels and the carbon aerogels obtained were investigated by TEM and N2 adsorption-desorption analysis. Relationships between the structure and adsorption property of the carbon aerogels and their precursor organic aerogels were studied by the adsorption of organic vapor. It was found that both the organic aerogels and the carbon aerogels have a higher static adsorption capacity for polar organic vapors than that for non-polar organic vapors. With an increase of pyrolysis temperature, the aerogels have a higher adsorption capacity for the non-polar benzene vapor with various concentrations and for the polar ethanol vapor with a low concentration, but have a lower adsorption capacity for the polar ethanol vapor with a high concentration. With an increase in the concentration of the organic vapors, the adsorption capacity of the aerogels for the non-polar benzene vapor only slightly increases whereas that for the polar ethanol vapor sharply increases. In addition, the desorption efficiencies of the various organic vapors on the organic aerogels and on their related carbon aerogels at room temperature are up to 60-85％, and that on the former is higher than that on the latter.

PAN基预氧化纤维表面超微结构的STM研究

XU Hai-ping, SUN Yan-ping, CHEN Xin-mou

2005, 20(04): 312-316.

Abstract(2091)

PDF(1691)

Abstract:
The ultrastructure of PAN-based preoxidized fibers prepared by a radio frequency plasma was investigated by scanning tunneling microscopy, and micrometer-, nanometer- and atom scale surface structural units in the preoxidized fibers were qualitatively defined. At the micrometer scale, microfibrils with different diameters and in strip-like form are aligned parallel to the fiber axis, and these microfibrils intersect each other. At the nanometer scale, the microfibrils are seen to be composed of closely packed and intertwined smaller fibrils. By making the scanning area smaller, it can be seen that the smaller fibrils are formed by chains of primary microcrystallites on the atomic scale, the carbon atoms on the surface of the preoxidized PAN fibers tend to be aligned but this is irregular compared with highly oriented pyrolytic graphite.

微氧化对二维炭/炭复合材料组织结构及试样宏观尺度的影响

LI Long, ZENG Xie-rong, LI He-jun, ZOU Ji-zhao, TANG Han-ling, WANG Mingfu

2005, 20(04): 317-323.

Abstract(2519)

PDF(1631)

Abstract:
The effect of low-level oxidation, defined as a weight loss less than 6% at 700℃-1300℃, on microstructure and volume change of 2D carbon/carbon (C/C) composites was measured by SEM and a micrometer. Results indicated that the oxidation rate of the C/C composites was linear. Higher temperature favored for surface oxidation, which leaded to an increased burn-off but a thinner oxidized layer. Lower temperature, however, favored in-depth oxidation, which led to a decreased burn-off but a thicker oxidized layer. Separation of the carbon fibers from the substrate could be seen, The tips of the fibers were sharpened and the volume of the composites decreased.

溶胶-凝胶中Fe催化剂用量对β-SiC堆积缺陷和形貌的影响

WU Xiang-yang, JIN Guo-qiang, GUO Xiang-yun

2005, 20(04): 324-328.

Abstract(2350)

PDF(1761)

Abstract:
Irregular β-SiC particles were prepared by a sol-gel and carbothermal reduction route, in which tetraethoxysilane and phenolic resin were employed to prepare carbonaceous silicon xerogels, the precursor of the SiC. The samples were characterized by XRD, FTIR, SEM and BET. Results indicated that β-SiC was not produced in the sol-gel process in the absence of Fe-catalyst and the existence of Fe enhanced the formation of β-SiC. With an increase in the amount of Fe catalyst, the average crystallite size of the SiC particles increased, whereas the stacking fault density and the surface area decreased.

超声波作用下炭黑的亲水性高分子聚合接枝

ZHAO Jian-yi, WANG Cheng-yang, LI Tong-qi

2005, 20(04): 329-334.

Abstract(2623)

PDF(2147)

Abstract:
To improve the dispersion stability of carbon blacks in water, polymer grafting on the surface of the blacks is commonly used. A free radical polymerization method was first used to graft a co-polymer of acrylic acid and a polymer containing sulfonic groups onto the surface of a furnace black under ultrasonic irradiation. The optimized conditions (pH, content of initiator and acrylic acid, reaction time) for high grafting ratios have been obtained. With the aid of XPS, FTIR and SEM analysis, the difference in surface functional groups and morphologies of the carbon blacks before and after grafting was investigated. It was found that ultrasonic waves significantly reduced the grafting time of acrylic acid. With the ultrasonic irradiation, the force acting between the as-grafted carbon blacks and water and the static repulsion among the carbon black particles were increased to a large degree. Together with the steric hindrance caused by the polymer molecules, the dispersion stability of carbon black in water was obviously improved.

针状焦基活性炭的制备及其作为EDLCs电极材料的电化学性能

LI Qiang, LI Kai-xi, WANG Fu-rong, SUN Guo-hua

2005, 20(04): 335-342.

Abstract(2608)

PDF(1937)

Abstract:
A series of high porosity carbons were prepared from raw needle coke activated by KOH. Nitrogen adsorption was used to characterize the BET surface area and pore structure of the porous carbon. When the ratio of KOH to carbon powder is 7∶1 and the heat treatment temperature 850℃, the BET surface area of the porous carbon obtained is 2728 m2/g, the pore volume is 2.14 cm3/g, the statistical average pore diameter is 4.4 nm, and ratio of the sum of macro and meso pore volume to the total pore volume is about 50%. The performance of the porous carbon electrode in 30% KOH was investigated. Its specific capacitance is 305 F/g, it has a relatively higher energy density, better power characteristics, and a more satisfactory electric double-layer capacitance performance than other samples.

热稳定化过程中PAN纤维热应力与热化学反应的关联性

LIU Jie, WANG Lei, ZHANG Wang-xi, LI Jia, LIANG Jie-ying

2005, 20(04): 343-349.

Abstract(2611)

PDF(1857)

Abstract:
The relationships between the thermal stress changes and the thermo-chemical reaction of six different PAN fibers during oxidative stabilization were studied using DSC, FTIR, EA, WAXD, and thermal stress analysis. Results show that the temperature for which a thermal stress begins and the temperature at which it reaches a maximum correlate well with exothermal start and peak temperatures from DSC. This indicates that the changes in thermo-chemical stress can be also used to characterize the speed and extent of the cyclization reaction of the PAN fibers. The changes in the thermal stress peaks can also be correlated with the changes in fiber structure, such as composition, element content, degree of domain orientation, aromatization index and density, implying that thermo-stress can be used control the fiber structure online during a continuous thermal stabilization process.

气体配比对硼掺杂碳纳米管生长特性的影响

WANG Zhi, BA De-chun, LIN Zeng, CAO Pei-jiang, LIU Fei, LIANG Ji

2005, 20(04): 350-354.

Abstract(2617)

PDF(1695)

Abstract:
Boron-doped carbon nanotubes (CNTs) were synthesized on porous silicon by electron cyclotron resonance chemical vapor deposition from CH4、B2H6 and H2 were used as the source gases and Fe3O4 nanoparticles as the catalyst. The effects of gas composition on the growth characteristics of boron-doped CNTs were investigated. Scanning electron microscopy, transmission electron microscopy and X-ray photoelec Boron-doped carbon nanotubes (CNTs) were synthesized on porous silicon by electron cyclotron tron spectroscopy were used to evaluate the structure and composition. Results show that addition of B2H6 influences the growth characteristic of CNTs greatly, making CNTs bend. Increasing the amount of B2H6 leads to a structural change in the CNTs from straight tubular to bamboo-like. Outer diameter increases from 60-90nm to 200-250nm, tube wall thickness increases from 10-20nm to 70-100nm, and a rougher surface and a decreased growth rate is noted. An increase in the B/C ratio of the specimen was detected as the amount of B2H6 increased. The B/C ratio can be up to 28∶72 when the B2H6/CH4 ratio is 2∶1.

乙炔催化裂解制备碳纳米带及其结构表征

ZHENG Rui-ting, CHENG Guo-an, ZHAO Yong, LIU Hua-ping, LIANG Chang-lin

2005, 20(04): 355-359.

Abstract(3017)

PDF(1956)

Abstract:
Carbon nanoribbons (CNRs) are obtained by Fe catalyzed chemical vapor deposition on a silicon substrate using C2H2 as carbon source. The morphology and microstructure of this novel carbonaceous material was observed by field emission scanning electron microscopey, high-resolution transmission electron microscopy and Raman spectroscopy. It is found that CNRs are of the order of 100μm long, and most have a nearly rectangular transverse section several hundred nanometers wide and 30nm thick. The carbon layers of the CNRs have an uniform orientation perpendicular to the ribbon axis; the orientation is characterized to be the (002) direction. The microstructure of the CNRs arises from stacked open sheets of carbon layers, and the ridges of carbon layers are folded every several layers. The arrangement of carbon layers in CNRs is not very regular, and many stacking faults have been found. Potential applications of CNRs as energy materials are suggested.

聚苯胺/氧化石墨的合成及其在DNA识别上的应用

ZOU Yan-hong, WU Jing, LIU Hong-bo, CHEN Zong-zhang

2005, 20(04): 360-364.

Abstract(2524)

PDF(2339)

Abstract:
Polyaniline-intercalated graphite oxide (PAn/GO) composites were synthesized by a procedure similar to an exfoliation/adsorption followed by in situ polymerization. The microstructure and electrochemical activity of PAn/GO composite were investigated by TEM, AFM, XRD and FTIR. Calf thymus single-stranded DNA (CTssDNA) and double-stranded DNA (CTdsDNA) were indentified by square wave voltammograms (SWV) using PAn/GO composite modified carbon paste as a working electrode. Results show that the PAn/GO composite in an ellipsoidal shape and with AN equivalent diameter of 60-70nm, aggregates to form chains and possesses electrochemical activity. A portion of PAn was intercalated into GO by two parallel chains, and the other portion was coated on the surfaces of the GO. The SWV redox potentials of a PAn/GO composite modified carbon paste electrode in CTssDNA and CTdsDNA solutions are 90.99mV and 18.00mV respectively.

类玻璃炭孔隙结构的TEM考察（英）

Tse-Hao Ko, Hsien-Lin Hu, Jyh-Ming Ting, Ying-Huang Chang

2005, 20(04): 365-368.

Abstract(2383)

PDF(1721)

Abstract:
Phenolic resin was heat-treated up to 2400℃ in an argon flow, leading to the formation of porous graphitized products. The microstructural changes in the graphitized phenolic resin were investigated by transmission electron microscopy. Some oval-shaped crystallites from 20 to 200nm and with very regular order have been found, which extend to the surface of the pores. In general, the larger the pores, the larger are the crystallites inside them, and there are smaller crystallites between the larger crystallites. The formation of the crystallites is due to the gas evolution reaction, evaporation of which creates an effect analogous to stress graphitization, leading to these highly directional crystallites at the edges and inside the pores.

影响活性炭纤维动态吸附氙性能的因素

CHEN Zhan-ying, WANG Xu-hui, WANG Ya-long, ZHANG Hai-tao

2005, 20(04): 369-372.

Abstract(3788)

PDF(1727)

Abstract:
The factors that influence dynamic adsorption capability of xenon on activated carbon fibers were optimized by orthogonal experimental design It was found that temperature, concentration and flow rate were the main factors that affect adsorption capability. Temperature had the greatest effect and concentration and flow rate had a comparable effect on adsorption capability.

炭/炭复合材料高温抗氧化涂层的研究进展

HUANG Jian-feng, LI He-Jun, XIONG Xin-bo, ZENG Xie-rong, LI Ke-zhi, FU Ye-wei, HUANG Min

2005, 20(04): 373-379.

Abstract(3250)

PDF(3289)

Abstract:
The recent development of oxidation protective coating materials for C/C composites, such as glass, noble metal, ceramics and multi-layer coating systems are reviewed. New advances in the traditional preparation technologies of carbon/carbon composite coatings and the exploitation of new techniques for the preparation of oxidation protective coatings in recent years are also introduced. Combined with the future applications of coated carbon-carbon composites in aviation, spaceflight and military fields, the next development direction in the investigation of the oxidation resistant coating is also proposed. It is shown that there is an obvious gap between the present research results and application in severe environments. The low preparation cost and long service life of the oxidation protective coating at high temperature and in a high rate gas eroding environment will be the main emphasis for future development. Improvement of the bonding between coating and matrix and the exploitation of new preparation techniques are the most important topics in for future research. Multi-layer and gradient ceramic coated carbon/carbon composites could work for a long time at high temperature and in a high gas rate eroding environment.

纳米门炭及纳米门电容器

2005, 20(04): 380-381.

Abstract(2513)

PDF(3017)

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持田勲教授和他的科研活动

SONG Yan, QIAO Wen-ming, Seong-Ho Yoon

2005, 20(04): 382-383.

Abstract(2243)

PDF(1627)

Abstract:
Prof. Isao Mochida was born in 1940. His doctorate degree was granted in 1968 from the Department of Synthetic Chemistry, University of Tokyo, Japan. In 1982, he was promoted to be a professor affiliated with the Research Institute of Industrial Science, Kyushu University (The institute was reorganized and renamed the Institute for Materials Chemistry and Engineering in 2003). He retired from Kyushu University in April 2004 and was appointed Professor Emeritus for his great contributions to scientific research. After retirement, he focuses his research on carbon nanofibers and activated carbon fibers.Prof. Mochida has produced brilliant achievements in the following fields: carbon science (mesophase pitch, needle coke, pitch and petroleum cokes, carbon fibers, activated carbon fibers, carbon nanofibers, mesoporous carbon, etc.), coal gasification and liquefaction and petroleum refining (hydrocracking, hydrorefining, coking of petroleum crude and products), catalysis (environmental protection, selective hydrogenation, catalytic elimination of sulfur and nitrogen species), and energy storage (direct methanol fuel cell, lithium battery, electric double layer capacitor, etc). Up to now, he has authored 10 scientific books, 720 technical papers and 50 patents and received 15 international and domestic awards because of his great scientific contributions. Prof. Mochida is also involved in many social activities, such as Chief Editor of Fuel in Asia (2003), the Advisory Committee for R&D Coal Utilization Technology (1995) and so on. He keeps active relationships with international coworkers and has close relationships with many companies in Japan, USA, Korea, China and other countries.

关于“Carbyne”的中文译名的一封信

2005, 20(04): 384-384.

Abstract(1339)

PDF(1608)

Abstract:

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