炭素
Online ISSN : 1884-5495
Print ISSN : 0371-5345
ISSN-L : 0371-5345
1999 巻, 187 号
選択された号の論文の10件中1~10を表示しています
  • K. Kaneko, N. Setoyama, G. Li, F. Okino, T. Ishikawa, M. Kanda, H. Tou ...
    1999 年 1999 巻 187 号 p. 71-76
    発行日: 1999/05/31
    公開日: 2010/06/28
    ジャーナル フリー
    N2 adsorption and XPS elucidated the surface states of fluorinated activated carbon fiber (F-ACF) and fluorinated carbon black. The XPS examination showed that the C-F bonds are not ionic, but covalent. The N2 adsorption isotherms of F-ACF was of Type I and the adsorption was predominant at a low P/P0 region, although the total adsorption amount of F-ACF decreased. The fluorination reduced the pore width of ACF by 0.21nm. Only external nanographitic layers of three stacking sheets were fluorinated, considering from the crystallite size from X-ray diffraction and the chemical analysis. The increase of the pore-wall thickness by the fluorination of the nanographitic sheets agreed with the decrease of the pore width by fluorination. Adsorption isotherms of H20, CH3OH, and C2H5OH were measured. The fluorinated ACF showed a perfect hydrophobicity. Also adsorption isotherms of CH3OH and C2H5OH on F-ACF had an S-shaped nature at the low P/P0 region, while their adsorption isotherms ofACF were of Type I.
  • Guobin Zheng, Hideaki Sano, Yasuo Uchiyama, Kazuo Kobayashi, Huiming C ...
    1999 年 1999 巻 187 号 p. 77-82
    発行日: 1999/05/31
    公開日: 2011/07/05
    ジャーナル フリー
    CF/SiC composites were prepared using polycarbosilane impregnation/pyrolysis technique and PAN-based carbon fibers heat-treated at 1400°C, 1500°C, 1600°C, 1800°C and 2000°C for 1 hour, respectively. The effect of heat treatment temperature (HTT) on the mechanical properties of the carbon fibers and the CF/SiC composites was investigated. With the increase of HTT, the crystallinity and elastic modulus of the carbon fibers were slightly improved, while the tensile strength of the carbon fibers reached highest values at the HTTs between 1400°C and 1600°C. However, the ultimate tensile loads (UTL) of the CF/SiC composites appear no direct relation with the strength of the carbon fibers. The CF/SiC composites with carbon fibers heat-treated at 1400°C exhibited a low tensile strength and completely brittle fracture. The composites with carbon fibers heat-treated at 1500°C and 2000°C exhibited a moderate UTL and short fiber pullout (lower than 5μm). The composites with carbon fibers heat-treated at 1600°C and 1800°C exhibited the highest UTL and longer fiber pullout (20-30μm). The difference was attributed to the change in the interface characteristics. With the graphitization degree of the carbon fibers being improved by the heat treatment, the surfaces of the carbon fibers became less active, and the fibers tended to bond weakly with the matrix. However, for the carbon fibers heat-treated at 2000°C, it was considered that the surface roughening might make the interface strong, resulting in lower strength and short fiber pullout. The above results suggest that the properties of CF/SiC composites can be controlled through heat treatment of the carbon fibers.
  • 藤本 宏之, 白石 稔
    1999 年 1999 巻 187 号 p. 83-87
    発行日: 1999/05/31
    公開日: 2010/06/28
    ジャーナル フリー
    The steepest descent method, one of the least square method was applied for the estimation method for thecarbon layer size distribution proposed by Diamond and the reliability was examined with X-ray diffraction patternsof mesocarbon microbeads heat-treated at lower temperatures. The layer size distribution calculated by the conventional matrix method showed negative histograms, whereas the method applied in the present study showed no such histogramswhich made possible to discuss about the relation between the heat treatment temperature and the average size anddistribution of carbon layer.
  • 白石 壮志, 岡 輝行, 大谷 朝男, 曽根田 靖, 山田 能生, 宮下 喜好, 小沢 達樹
    1999 年 1999 巻 187 号 p. 88-95
    発行日: 1999/05/31
    公開日: 2011/07/05
    ジャーナル フリー
    One dimensional carbon structure (carbyne) was tried to be synthesized through electrochemical defluorinationof polytetrafluoroethylene (PTFE) in nonaqueous electrolytes. When tetrahydrofuran (THF) solution containingtetrabutylammonium perchlorate (TBAP) was used as electrolyte, the electrochemical defluorination of PTFEproceeded sufficiently with the potentiostatic reduction at 0 V vs. Li/Li+. According to the results with Raman analysis, it was found that polyacetylene structure were contained in the defluorination products. The FTIR spectrum suggestedthe existence of triple bond of carbon atoms in the defluorination products. On the other hand, the electrochemical defluorination did not so proceed in THF solution containing lithium perchlorate (LiClO4) at OV vs. Li/Li+. Moreover, triple bond of carbon atoms was not found when LiClO4/THF was used. Considering the stability against electrochemicalreduction of these two electrolytes, it can be concluded that decomposed species of TBAP promote the defluorinationof PTFE.
  • 収着への嵩密度・細孔の影響
    豊田 昌宏, 盛屋 考治, 稲垣 道夫
    1999 年 1999 巻 187 号 p. 96-100
    発行日: 1999/05/31
    公開日: 2010/06/28
    ジャーナル フリー
    It was found that an exfoliated graphite (EG) can sorb a large amount of heavy oilvery quickly. Maximumsorption capacity on EG was shown to be about 80g of heavy oil per 1 g of EG, which is much largr than the packageof absorbents have ever been used. Sorption time of A-grade oil was so quick as to complete within 1 min. On EGsamples compacted to different volumes which had high bulk density, small surface area and total pore volume, lessmaximum sorption capacity was observed; the one having the higher bulk density sorbed the less amount of heavy oil. Time to reach maximum sorption, as well as sorption capacity, for an exfoliated graphite depended on bulk densityand pore.
    On observation through SEM and porosimeter, differences of morphology on exfoliated graphite were detected. The sorption capacity and time for sorption of heavy oil into exfoliated graphite were supposed to depend strongly onthe size and shape of pores in exfoliated graphite.
  • 小島 昭, 佐藤 誠, 山田 徹郎
    1999 年 1999 巻 187 号 p. 101-108
    発行日: 1999/05/31
    公開日: 2010/06/28
    ジャーナル フリー
    A large amount of activated sludge adhered to carbon fiber when they were immersed in activatedsludge. When carbon fiber was immersed in a cistern containing polluent river water, thetransparency of thewater increased and biochemical oxygen demand (BOD) value decreased. The action of such microorganisms that adhered to the carbonfiber are expected to be uttilized for the purification of river, lake, marsh anddam water. Theaggregation of carbon fiber and sludge formed aerobes exterior and anaerobes interior. It is thought the BOD in waterwas decomposed H2O, CO2 and so on by the action of this biome. Carbon fiber could function as filters and amedium for the microbital adhesion. Carbon fiber with high elasticity and small diameter could effectively come in contactwith polluted water by being free to move in the water.
  • 西澤 節
    1999 年 1999 巻 187 号 p. 109-115
    発行日: 1999/05/31
    公開日: 2011/07/05
    ジャーナル フリー
  • 向井 昭郎
    1999 年 1999 巻 187 号 p. 116
    発行日: 1999/05/31
    公開日: 2010/06/28
    ジャーナル フリー
  • 結晶子のa方向の大きさLaより, c軸方向のLc(またはその逆)の方が大きい黒鉛材料は合成できますか?
    都竹 卓郎
    1999 年 1999 巻 187 号 p. 118
    発行日: 1999/05/31
    公開日: 2010/06/28
    ジャーナル フリー
  • 1999 年 1999 巻 187 号 p. 132
    発行日: 1999年
    公開日: 2011/03/01
    ジャーナル フリー
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