TANSO

Tailoring of Nanostructure of Carbons

Nanocarbons and New Functions

Morinobu Endo

2001 Volume 2001 Issue 200 Pages 202-205
Published: December 20, 2001
Released on J-STAGE: June 28, 2010

DOIhttps://doi.org/10.7209/tanso.2001.202

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Nanocarbons, which are obtained by controlling the structure in nanometer scale as well as bonding nature of carbon atoms, can provide the highly functionalperformances. The properties might be very different from those of conventional carbons. As one of the example of nanocarbons with one dimensionality, the carbon nanotubes and vapor grown carbon fibers with thin diameter less than 100nm can exhibit the quantum effect in transport properties, which are very different from those of carbon fibers. In the present paper, preparation and properties of nanocarbons, con-sisting of something tailor-made carbon hexagonal networks, are demonstrated.

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Review on the Structural Concepts of Carbons. Molecular, Nano, Meso and Micro-scopic Views of Mesophase Pitch/ Graphitized Fiber Including Nano Phased Fibers As Models of Carbons

Isao Mochida

2001 Volume 2001 Issue 200 Pages 206-216
Published: December 20, 2001
Released on J-STAGE: June 28, 2010

DOIhttps://doi.org/10.7209/tanso.2001.206

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Structural concepts of carbon materials arc riviewed from molecular. nano, meso and micro-scopic views, picking mesophase pitch/ graphite fiber including nanofiber as models of carbon in order to understand the carbon and design the materials of better performance. The graphitic materials are viewed on the structural units of hexagon plane. graphite crystal, nano, meso and micro-scopic units. Mesophase pitch as a precursor of graphite fiber was viewed on the same concepts to correlate the structures of the starting and product materials and to control the structure of the graphite fiber. Glassy and active carbons were also viewed from the same standpoints of structural concepts to expand their properties. Structures of nano phased materials of particle and fiber forms were also elucidated.

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Analysis of Carbon Layer Size Distribution of MCMB by the Diamond's Method

Second Report

Hiroyuki Fujimoto

2001 Volume 2001 Issue 200 Pages 243-248
Published: December 20, 2001
Released on J-STAGE: June 28, 2010

DOIhttps://doi.org/10.7209/tanso.2001.243

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The analysis method proposed by Diamond for estimating the carbon layer size distribution was improved by considering the coherent scattering from the hetero atoms and methylene bridges and incoherent scattering, and mesocarbon microbeads heat-treated at several temperatures were analyzed by the method. The fitting accuracy of 11 band by the least square method was fairly improved compared with that previously reported. However, the obtained size distribution by the method differed from that estimated from the TEM observation. The TEM observation showed that the carbon layer plane is not planar but zigzag in the earlier stage of carbonization. Since the 11 band is an in-plane reflection, the reflection is caused only by the unit of planar part in the zigzag layer plane. Hence, the estimated size of carbon layer plane is apparently smaller than that of real plane observed by TEM. As a result, the H/C atomic ratio calculated from the Diamond's method become larger than that from elemental analysis.

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Character of Charcoal Made from Used Paper and Growth of Basidiomycetes Cultivated on the Charcoal

Takao Imanishi, Hiroaki Yasue, Mitsuhiro Sakawa

2001 Volume 2001 Issue 200 Pages 249-254
Published: December 20, 2001
Released on J-STAGE: June 28, 2010

DOIhttps://doi.org/10.7209/tanso.2001.249

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The authors have investigated characteristics of charcoal made from used paper and mycelial growth in this charcoal, in order to utilize used paper as medium material of the basidiomycetes. The pH of the charcoal increased with carbonization temperature, which was lower than that of charcoal made from wood at the same temperature. Charcoal with the pH favorable for the basidiomycetes growth was obtained easily. The mycelial extension of Pleuroutus ostreatus in charcoal was the most remarkable at pH 6.0 which was suitable for growth of mycelium. When the bulk density of charcoal was 0.15g/cm³, the radius of 80% of the pores were in the range from 1μm to 100μm, the size of which was suitable for the mycelial growth. High moisture rate was necessary for mycelial extension of Pleuroutus ostreatus in charcoal than in sawdust. It has been proved that Pleuroutus ostreatus grows up well in charcoal made from used paper.

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Strengthening of PAN-Based Carbon Fibers by Imposing a High Magnetic Field in a Carbonization Process

Mun-Gyu Sung, Kensuke Sassa, Kunihiko Inoue, Hiroyasu Ogawa, Masao Doy ...

2001 Volume 2001 Issue 200 Pages 255-260
Published: December 20, 2001
Released on J-STAGE: June 28, 2010

DOIhttps://doi.org/10.7209/tanso.2001.255

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Carbon fibers produced from PAN (polyacrylonitrile) as a precursor are generally subjected to the three heat treatment processes of stabilization and carbonization followed by graphitization. The fibers that had been stabilized in the first process were carbonized in a high magnetic field imposed parallel to fiber axis at the temperature of 1445K and graphitized without magnetic field at 2273K. The tensile strength of these treated fibers was increased in 15-31% in comparison with that of the fibers treated in no magnetic field. The reason why the imposition of the magnetic field could improve the strength of fibers has been studied through the methods such as a microscopic observation of fiber surfaces, a statistical Weibull analysis, an X-ray diffraction and a Raman spectroscopy. By using of the observed and measured results, the mechanism of strengthening of PAN-based carbon fibers by imposing the high magnetic field has been discussed on the basis of an intermolecular cross-linking reaction in terms of a radical pair theory in a magnetic field.

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Carbon-Related Materials for Hydrogen Storage Functions

Past Experimentals, Theories/Simulations, and Future Prospects

Shin-ichi Orimo, Tomoyoshi Matsushima, Hironobu Fujii

2001 Volume 2001 Issue 200 Pages 261-268
Published: December 20, 2001
Released on J-STAGE: July 05, 2011

DOIhttps://doi.org/10.7209/tanso.2001.261

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In this review, we first summarize recent experimental and theoretical/simulation researches on various carbon-related materials for hydrogen storage functions. Based on these researches, it would be, we propose, indispensable to design weakly chemisorbed (bonded) sites for atomistic hydrogen in carbon-related materials for better functions. Actually, the mechanically prepared nanostructured graphite is reported to exhibit the notable hydrogen storage functions, probably due to the formation of weakly chemisorbed (bonded) sites. Potential activities of carbon-related materials for hydrogen storage functions are critically, but still positively, described in the review.

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[title in Japanese]

[in Japanese]

2001 Volume 2001 Issue 200 Pages 269
Published: December 20, 2001
Released on J-STAGE: June 28, 2010

DOIhttps://doi.org/10.7209/tanso.2001.269

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[title in Japanese]

2001 Volume 2001 Issue 200 Pages 271
Published: December 20, 2001
Released on J-STAGE: June 28, 2010

DOIhttps://doi.org/10.7209/tanso.2001.271

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