TANSO
Online ISSN : 1884-5495
Print ISSN : 0371-5345
ISSN-L : 0371-5345
Volume 2000, Issue 195
Displaying 1-26 of 26 articles from this issue
  • Eiichi Yasuda
    2000 Volume 2000 Issue 195 Pages 329-331
    Published: December 20, 2000
    Released on J-STAGE: March 01, 2011
    JOURNAL FREE ACCESS
    The project of “Carbon Alloys” supported by Japanese government was successfully finished after three years research. The outline, the results and the future of this concept of the project were summarized.
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  • Tatsuo Oku, Masayuki Nakata, Akira Kurumada, Kiyohiro Kawamata
    2000 Volume 2000 Issue 195 Pages 332-335
    Published: December 20, 2000
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    Effect of compressive prestress on the correlation between thermal conductivity and Young's modulus of carbon materials, fine-grained isotropic graphite IG-430U and a felt type C/C composite CX-2002U, was examined. Young's modulus and thermal conductivity decreased due to compressive prestress. The change in thermal conductivity of carbon materials was related to that of Young's modulus via sound velocity. The decrease in thermal conductivity of IG-430U graphite due to prestress was mostly correlated with that in Young's modulus. Also, decrease in thermal conductivity of C/C composite showed the similar tendency as the case for the graphite.
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  • Keiko Kawashima, Hidefumi Takahashi, Masuo Shimazaki, Tohru Kohno, Hid ...
    2000 Volume 2000 Issue 195 Pages 336-340
    Published: December 20, 2000
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    Carbon fibers have been subjected to surface treatment by amination in order to improve adhesion strength between the fibers and an epoxy resin at carbon fiber reinforced plastic (CFRP). XPS measurements confirmed the introduction of amino groups on the surface of carbon fibers by fuming nitric acid treatment followed by the reduction with sodium dithionate. The tensile strength of a single fiber was not affected by the amination of the surface. The interfacial shear strength (τ) of unmodified, nitrated and aminated carbon fibers was evaluated with the single fiber embedded test specimens. The introduction of amino groups was shown to improve the interfacial shear strength by about 30 % as compared with the unmodified fiber.
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  • Study on Cluster Formation Mechanism of Water Molecules Carbon Micropores by using in situ Small Angle X-ray Scattering
    Taku Iiyama, Katsumi Kaneko
    2000 Volume 2000 Issue 195 Pages 341-346
    Published: December 20, 2000
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    The in situ small-angle X-ray scatterings (SAXS) of water adsorbed on pitch-based activated carbon fibers (ACF) of pore width w=0.8 and 1.1nm were measured at 303K and different relative pressures. The SAXS spectrum of ACF of w=1.1nm on desorption course did not overlap that on adsorption course, showing hysteresis. The density fluctuation data from Ornstein-Zernike analysis for the SAXS profiles indicated that water molecules form great clusters in the course of adsorption, but desorption proceeds through uniform molecular evaporation. These results indicate the formation of water molecular clusters in the hidden surface spaces. The in situ SAXS analyses can give an essential information for the design of new carbon-alloy materials by molecular adsorption.
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  • Noriyuki Kurita, Makoto Sasaki
    2000 Volume 2000 Issue 195 Pages 347-352
    Published: December 20, 2000
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    As a new carbon-based material for promising anode materials of rechargeable lithium ion batteries, BCN ceramics with a large amount of BNB units in a graphite-like sheet have been synthesized. In this study, we employed a polyaromatic hydrocarbon C96H24 as a model cluster for the graphite-like sheet and investigated the effect of BNB-unit substitutions on the electronic and Li-absorption properties of the sheet, by using a semiempirical molecular orbital method. The results are summarized as follows.
    (1) BNB substitutions prefer to occur at the periphery of C96H24 sheet, and the structures with more BN bonds are more stable.
    (2) By BNB substitutions, the surface of the potential energy for Li-absorption on the substituted sheets is largely changed to make the B-substituted sites more preferable for Li-absorptions.
    (3) Depending on the number of BNB-substitutions, the distribution of LUMO is remarkably changed, resulting in the change of Li-absorption sites.
    (4) Li absorption energies on the BNB-substituted sheets are larger than that on the B-substituted sheet.
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  • Toru Kuzumaki, Yasuhiro Horiike, Hideki Ichinose
    2000 Volume 2000 Issue 195 Pages 353-359
    Published: December 20, 2000
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    An electron emitter which is made of carbon nanotubes and C60 crystals has been produced by wire drawing process. The nanotubes were aligned along the longitudinal direction of the wire. The emission current against the applied voltage of the emitters indicated different behavior at the first emission and the second hereafter . After the second run the emission begun at rather lower voltage. TEM observations have revealed that a protrusion arose at the tip of the nanotube after field emission. The result suggests that the I-V characteristic of the emitter is affected by the tip structure of the nanotube. The experiments lead us to a new concept of a high efficiency carbon-based electron emitter.
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  • Tomohiro Kobayashi, Masaya Iwaki, Takayuki Terai
    2000 Volume 2000 Issue 195 Pages 360-364
    Published: December 20, 2000
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    The changes of composition and structure of polyimide films due to high-energy irradiation and high-dose implantation were studied by surface characterization techniques and the electric resistance measurement. Polyimide (C22H10N2O5) n film specimens were irradiated with 4 MeV Ni3+ ions for the fluences from 3.5×1012cm-2 to 1.0×1016cm-2. After irradiation with the fluence of 1.0×1016cm-2, the ratios of N/C and O/C decreased from 0.089 and 0.244 to 0.018 and 0.086, respectively. The generation of amorphous carbon areas dispersed in the irradiated polyimide film was suggested by Raman spectroscopy and electric resistance measurement. Nano-sized metallic particles were produced in the films by 130 keV silver ion implantation. The diameter of the particles was about 5 nm for the specimen implanted with 1×1016cm-2 and it increased with the implantation dose. On the other hand, no particles were observed in the specimen implanted with tungsten ion.
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  • Masayuki Kawaguchi, Yuichi Wakukawa, Nobuhito Ohno
    2000 Volume 2000 Issue 195 Pages 365-370
    Published: December 20, 2000
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    Crystallinity of a graphite-like layered material, BC6N was evaluated by X-ray diffraction and Raman spectroscopy. The in-plane atomic arrangement of the material was estimated by using a semi-empirical molecular orbital calculation. The BC6N prepared by CVD (Chemical Vapor Deposition) at 1800°C had the crystallite size Lc of 9.68nm which was much larger than that of BC6N2 previously prepared by the pyrolysis of the adduct, (CH2CHCN) 2: BCl3. On the other hand, the BC6N showed a broad Raman spectrum with a large D-band. This is explained by the alloying of B and Natoms in the graphite network, which introduced the variety of chemical bonds and diminished the size of graphite crystals. Among the calculated 10 types of the atomic arrangements, 2 candidates are the most favorable for the BC6N prepared in this study from the standpoint of the topology based on the chemical reaction. Thermodynamically stable arrangements would be made by the reaction at higher temperature or by using the physical enhancement, which could break the precursors into atomic species.
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  • Degradation of sec-Alcohols
    Hiromi Yamashita, Masaru Harada, Akihiro Tanii, Junko Misaka, Masakazu ...
    2000 Volume 2000 Issue 195 Pages 371-377
    Published: December 20, 2000
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    Preparation of titanium oxide photocatalysts loaded on activated carbon fiber (ACF) using an ionized cluster beam (ICB) method and their photocatalytic reactivity for the oxidative degradation of organic pollutants (alkyl alcohols, phenol) diluted in water were investigated. The utilization of the ICB method under oxygen atmosphere enables the preparation of titanium oxide photocatalysts on ACF relatively low temperature without causing any damages t the supports. Characterization using spectroscopic techniques indicates that fine particles of TiO2 having a quantum size effect are formed on the supports mainly as an anatase structure. The combination of the photocatalytic reactivity of TiO2 and the adsorption ability of ACF was effective for the degaradation of oraganic pollutants diluted in water into CO2 and H2O.
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  • Hiroshi Iwanaga, Yuka Nakamoto, Tatsunori Hidaka, Shin Takeuchi
    2000 Volume 2000 Issue 195 Pages 378-382
    Published: December 20, 2000
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    Fracture strengths of commercial carbon fibers were measured under a combined torsion-tension deformation, where a carbon fiber was stretched after twisting many turns around the fiber axis. The tensile fracture strength decreased parabolically towards zero with increasing number of turns, exhibiting incline fracture surface. The results of a low modulus pitch-based carbon fiber (XN-05 from Nippon Graphite Fiber Co.) agree quite well with the theoretical relation derived on the assumption that the fracture occurs when the local tensile stress reaches a critical stress. This fact is consistent with the fact that the fiber has an almost isotropic amorphous-like structure. The results for a PANbased carbon fiber (M60J from Toray Co.) consisting of anisotropic graphite layers show a deviation from the theoritical curve indicating an anisotropic strength of the fiber.
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  • Masaki Narisawa, Kentaro Yamane, Kiyohito Okamura, Masayoshi Itoh
    2000 Volume 2000 Issue 195 Pages 383-387
    Published: December 20, 2000
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    The thermosetting resin having 94 wt% of a high ceramic yield, MSP (-Si (C6H5)-C≡C-C6H4-C≡C-), was hybridized with silica by a Sol-Gel method. The hybrids were shaped into pale yellow transparent tablets by casting. The obtained tablets kept their shape during the pyrolysis up to 1273K without macroscopic cracks. By the hybridization with silica, the obtained materials after the pyrolysis shows higherresistance to the oxidation as comparedwith the materials merely derived from MSP. The dense silica layer formation on the surfaces played a role in increasing the oxidation resistance.
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  • Tsutomu Takeichi, Yutaka Yamazaki, Taketo Fukui, Akihiko Matsumoto, Mi ...
    2000 Volume 2000 Issue 195 Pages 388-394
    Published: December 20, 2000
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    Porous carbonized films were prepared by the pyrolysis of poly (urethane-imide) films that were prepared by reacting polyurethane prepolymer and poly (amide acid), a precursor of polyimide. The reaction between the two prepolymers gave poly (urethane-imide) films that have network structure. By treating the poly (urethane-imide) films at 300-400°C thermally labile urethane domains decomposed, leaving porous polyimide films. The average macropore size of the films was 0.6-51-μm depending on the ratio of the urethane and imide components. The porous polyimide films were then pyrolyzed at 900°C to give porous carbonized films maintaining the pore structure at the porous polyimide films. It was revealed fromthe nitrogen adsorption isotherm study for the macroporous carbonized films that the films also contain micropores that are developed during the pyrolysis of the macroporous polyimide films.
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  • Soshi Shiraishi, Daisuke Hiruma, Yoshikazu Onuma, Asao Oya, Tien-Tzu L ...
    2000 Volume 2000 Issue 195 Pages 395-399
    Published: December 20, 2000
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    Polytetrafluoroethylene (PTFE) was defluorinated (carbonized) with lithium-naphthalene complex (radical anion) dissolved in dimethoxyethane. The defluorinated-PTFE exposed in air was found to be composed of fine LiF p articles and amorphous carbon matrix after heating at 70°C-700°C. Porous carbons with high BET specific surface area (1000-1800m2/g-1) were obtained by removal of LiF from these defluorinated PTFE using dilute HCI solution. The results of X-ray diffraction and N2 adsorption measurement suggested that the formation of mesopores in the porous carbons obtained was owing to the presence of LiF fine particle in the matrix carbon.
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  • Ryoko Ono, Masaki Hosoda, Masahiko Okuzawa, Miho Tagawa, Chuhei Oshima ...
    2000 Volume 2000 Issue 195 Pages 400-404
    Published: December 20, 2000
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    By chemical vapor deposition, we have tried to grow epitaxial films of graphene nano-ribbons on Pt (755) and TiC (755) surfaces. Some properties of these graphene films have been clarified by X-ray photoelectron spectroscopy, low energy electron diffraction, and angle-resolved ultraviolet photoelectron spectroscopy. Nano-ribbons have not been prepared on Pt (755), but they have successfully been prepared on TiC (755). Quantized n bands and new electronic states at E, have been found in the photoemission spectra.
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  • Naoya Miyajima, Eiichi Yasuda, Brian Rand, Takashi Akatsu, Kinichi Kam ...
    2000 Volume 2000 Issue 195 Pages 405-409
    Published: December 20, 2000
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    The difference between the effects of bromine and iodine treatment in the carbonization of pitches (coal tar pitch and petroleum pitch) has been investigated by adsorption isotherms, XPS and TG-Mass measurements, in order to understand the stabilization mechanism of pitches by halogen. A replacement reaction between bromine and the hydrogen in the hydrocarbon molecules in the pitches was one of the most dominant reactions of the bromine treatment. This was independent of the chemical structure of the parent pitch and resulted ina high carbon yield both in coal tar pitch and in petroleum pitch. The stepwise dehydrogenation, detected as the removal of HBr caused by cleavage of-C-Br bonds, continued up to high temperatures in the carbonization process. It is suggested that bromine-substituted compounds are thermally stable and enhance the dehydrogenation up to about 600°C.These results are very different from iodine treatment, which promotes dehydrogenative polymerization via the formation of charge-transfer complexes.
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  • Yoshiko Ohashi, Tatsuya Hironaka, Toshiharu Kubo, Kazuo Shiiki
    2000 Volume 2000 Issue 195 Pages 410-413
    Published: December 20, 2000
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    The magnetic field dependence of the transverse magnetoresistance Δρ/ ρ0 and the Hall coefficient RH was measured for the graphite films of various thickness ranging from around 20 to 110 nm at temperatures between 4.2 K and 300 K. High quality of the crystallinity of these graphite films prepared by cleaving could be confirmed from the observation of Shubnikov-de Haas oscillation in RH. The saturation tendency revealed in the resistivity ρ versus magnetic field B characteristics for graphite films thinner than about 50 nm in the strong magnetic field region at low temperature, while as for all graphite films in this study, ρ varied in proportion to Bn (n>1) in the strong magnetic field region at high temperature. According to the transport theory for the simple two carriermodel in the strong magnetic field region, this saturation tendency should be due to the differencebetween electron and hole densities. It may be caused by some change of energy band structure in thin films. Furthermore, at high temperature, ρ versus B characteristics, common to all these graphite films, may be explained by the equal number density ofelectrons and holes due to thermal excitation.
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  • Takeshi Abe, Yasuo Mizutani, Minoru Inaba, Zempachi Ogumi
    2000 Volume 2000 Issue 195 Pages 414-419
    Published: December 20, 2000
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    FeCl3-based graphite bi-intercalation compounds (GBCs) were prepared from stage 5 FeCl3-graphite intercalation compound and their formatiomechanism, stacking sequences, and lattice dynamics were studied. Bi-intercalated species were H2SO4, IBr, ICl, and SbCl5. From the stacking sequences determined by X-ray diffraction measurements, bi-intercalation processes were found to be affected by the electron affinity of bi-intercalated species. Lattice dynamics of the resultant GBCs was investigated by Raman spectroscopy. In the Raman spectra of GBCs with one bi-intercalated layer, two peaks assigned as Raman active E (2) i2g and E (2) b2g mode frequencies were obtained, and both frequencies were affected by the bi-intercalated species. Raman spectra of GBCs with two bi-intercalated species gave two E (2) b2g mode frequencies due to the double-intercalate coupling effect.
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  • Osamu Yamamoto, Taiki Fukuda, Jun Sawai, Mitsumasa Kimata, Tadashi Sas ...
    2000 Volume 2000 Issue 195 Pages 420-423
    Published: December 20, 2000
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    An ion-exchange resins were treated for I h by an aqueous solution of MgSO4 with a concentration of 1 mol dm-3 and they were carbonized for 1h in a high purity N2 gas at the temperature range from 300 to 1000°C. For the obtained spherical carbon containing MgO, the bactericidal effects for Escherichia coli were studied by colony count method. From XRD measurements of carbonized resins, MgO of cubic phase was detected and no graphite was observed. The amount of MgO in the carbon samples was a constant value of 30wt%, irrespective of the carbonization temperature of an ion-exchange resin exchanged by Mg2+. From the results of bactericidal tests, it was found that the antibacterial activity increased with the increase of the crystallinity of MgO dispersed in carbon samples, i.e., the increase of carbonization temperature. On the sample carbonized at 1000°C, it was clarified to show the bactericidal action for Escherichia coli.
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  • Mauricio Terrones, Takuya Hayashi, Kunio Nishimura, Morinobu Endo, Hum ...
    2000 Volume 2000 Issue 195 Pages 424-433
    Published: December 20, 2000
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
    Nanotube research has developed rapidly over the last decade, following the bulk production of C60 and structural identification of carbon nanotubes. This review summarises achievements in nanotube and nanofibr technology, in particular, various routes to filamentous carbon and their remarkable mechanical and electrical conducting properties. These advances are paving the way to nanoscale technology and promise to provide a wide spectrum of applications.
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  • Kouichi Miura
    2000 Volume 2000 Issue 195 Pages 434-440
    Published: December 20, 2000
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
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  • Hiroaki Hatori
    2000 Volume 2000 Issue 195 Pages 441-445
    Published: December 20, 2000
    Released on J-STAGE: June 28, 2010
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  • Naoki Okuyama
    2000 Volume 2000 Issue 195 Pages 446-450
    Published: December 20, 2000
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
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  • Seiichi Uemura
    2000 Volume 2000 Issue 195 Pages 451-460
    Published: December 20, 2000
    Released on J-STAGE: June 28, 2010
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  • [in Japanese]
    2000 Volume 2000 Issue 195 Pages 461
    Published: December 20, 2000
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
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  • 2000 Volume 2000 Issue 195 Pages 463-464
    Published: December 20, 2000
    Released on J-STAGE: June 28, 2010
    JOURNAL FREE ACCESS
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  • [in Japanese], [in Japanese], [in Japanese]
    2000 Volume 2000 Issue 195 Pages 465-468
    Published: December 20, 2000
    Released on J-STAGE: June 28, 2010
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