TANSO

Graphitization Behavior of the Soot Produced by Burning of the Cure Mixture of NH₄ClO₄/HTPB

Kazuro Kawamura, Eiichi Yasuda, Yasuhiro Tanabe, Shushichi Kimura

1995 Volume 1995 Issue 167 Pages 89-93
Published: May 20, 1995
Released on J-STAGE: June 28, 2010

DOIhttps://doi.org/10.7209/tanso.1995.89

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The particle feature and the graphitization behavior were studied for the soot produced by burning of the cure mixture of NH₄ClO₄ and hydroxyterminated polybutadiene (HTPB) under N₂ gas pressure of 0.49 and 6.9 MPa. The soot particles appeared cluster including chain-like structure. The size of particles and the distribution of carbon layer segments of the soot depended on the HTPB content and the burning pressure. The pattern of gathering of carbon layer segments was irregular very much when the large content of resin and low burning pres-sure were applied. The structural change and shape change from spherical to polygonal were remarkable when the soot was heat-treated at the temperature above 1500°C. At a heat treat-ment temperature (HTT) of 2800°C, the value of interlayer specing, d₀₀₂, was more than 0.3425nm, and that of the crystallite size, L_c, was below 11nm. Moreover, many structural defects could be seen in stacking layers of polygonal particles. On plotting of log L_c vs d₀₀₂ for the soots heat treated at various temperatures, a straight relationship was observed at the region of d₀₀₂>0.3425nm.

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Modification of Pore Structure in Carbon Molecular Sieve Films Prepared from Polyimide

Hiroaki Hatori, Yoshio Yamada, Minoru Shiraishi, Hiroshi Nakada, Suehi ...

1995 Volume 1995 Issue 167 Pages 94-100
Published: May 20, 1995
Released on J-STAGE: June 28, 2010

DOIhttps://doi.org/10.7209/tanso.1995.94

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It has been found that carbon molecular sieve (CMS) film prepared from Kapton-type polyimide shows a high selectivity in permeation of gases. For example, carbon dioxide permeates through the film 50 times faster than nitrogen. Since the property is governed by the micropore structure, modification of micropore size distribution was studied on this CMS film. The micropore size varies with heat-treatment temperature; as a result, polyimide film with the thickness of 25μm gave CMS films having sieving property comparable to zeolite 4A or 5A. CMS films prepared from polyimide film of 125μm had smaller size and volume of micropore than the thinner films treated at the same temperatures. On the other hand, change in molecular orientation in pristine film, which influences the graphitizability remarkably, was not effective for modifying the pore structure in CMS film.

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Analysis of Stacking Structure of Meso-carbon Micro-beads: Patterson Function Method and Its Reliability

Hiroyuki Fujimoto, Minoru Shiraishi

1995 Volume 1995 Issue 167 Pages 101-107
Published: May 20, 1995
Released on J-STAGE: June 28, 2010

DOIhttps://doi.org/10.7209/tanso.1995.101

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It is well known that the structure analysis with the Patterson function provides a powerful tool in X-ray crystallography and many researchers have applied it for various carbon materials. In the present study, the effect of variation of sampling distance in the measurement of 002 diffraction profiles on the Patterson function in relation to the reliability of the analysis was investigated using the sampling theorem and the structural change of mesocarbon microbeads (MCMB) by heat treatment was analysed on this basis. Thereby, the Patterson functions calculated from 002 diffraction profiles with sampling distance of Δ (2θ) ≤0.5° are found to contain many Fourier ripples and aliasing effect, whereas very few ripples and aliasing effects in those obtained with Δ (2θ) ≤0.1° A 30 Å band was observed for MCMBs heat-treated below 800°C, giving rise to the modulation in oscillation curves of the Patterson functions. Such a result is in agreement with that reported by Hirsch for coals.

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Characterization of Air Blown Pitches with ESR

Jae Hoon Choi, Haruo Kumagai, Yuzo Sanad

1995 Volume 1995 Issue 167 Pages 108-115
Published: May 20, 1995
Released on J-STAGE: June 28, 2010

DOIhttps://doi.org/10.7209/tanso.1995.108

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Reactions of coal tar and petroleum pitches with air blowing process for carbon fiber precursorswere investigated. Air and nitrogen blown pitches were divided into several fractionswith solvent extraction. The fractions were characterized with electron spin resonance (ESR).Structural features of the pitches were well represented by the ESR parameters, such as spinconcentration (Ns), shapes of spectra, and peak-to-peak linewidth (ΔHpp) which had good relationshipswith molecular weight, the size of condensed aromatic ring, and hydrogen contents.It is supposed that coal tar pitch was much sensitive to air blowing process rather than that ofpetroleum pitch. Development of polycondenced structure at the stage of mesophase transformationwas restricted in the air blowing process.

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Characterization and Modification of Carbon Material Surface

Masanori Nakahara, Yuzo Sanada

1995 Volume 1995 Issue 167 Pages 116-124
Published: May 20, 1995
Released on J-STAGE: June 28, 2010

DOIhttps://doi.org/10.7209/tanso.1995.116

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Characterization of carbon surface has been investigated by spectroscopic methods includingX-ray photoelectron spectroscopy, laser Raman spectroscopy, and FT-IR attenuated totalreflection technique. Changes of the surface with oxidation have been clarified from theview point of surface graphitic structure and oxygen-containing functional groups. The speciesof surface functional groups formed by the oxidation are closely responsible for the surfacegraphitic structure in character. The electrochemical treatments with ammonium hydrogencarbonate, sulfuric acid, and tetraethylammonium hydroxide solutions are tested. The addition ofcarboxyl groups is accompanied by the destruction of the surface graphitic structure. For theammonium hydrogencarbonate electrolyte, the surface is able to be modified through the gradualdestruction of the graphitic structure. Oxygen plasma treatment removes less ordered structurepresent on the edge surface. As a result, keto-enol structure is added to the surface. Hydroxylgroups added to the edge surface play an important role in improving the adhesion betweenthe edge surface and epoxy resin. On the other hand, PVC would interact with functionalgroups containing a>C=O group present on the edge surface. Information obtained from thisstudy can be applied to modify and control interfacial region in carbon fiber reinforced composites.

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Studies on Electronic Properties of Carbon Materials in the Last Half Century

Part III

Takuro Tsuzuku

1995 Volume 1995 Issue 167 Pages 125-132
Published: May 20, 1995
Released on J-STAGE: June 28, 2010

DOIhttps://doi.org/10.7209/tanso.1995.125

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[title in Japanese]

[in Japanese]

1995 Volume 1995 Issue 167 Pages 139
Published: May 20, 1995
Released on J-STAGE: June 28, 2010

DOIhttps://doi.org/10.7209/tanso.1995.139

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[title in Japanese]

[in Japanese]

1995 Volume 1995 Issue 167 Pages 142-143
Published: May 20, 1995
Released on J-STAGE: June 28, 2010

DOIhttps://doi.org/10.7209/tanso.1995.142

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