Composite materials were prepared by multi-layer fabrics and epoxy resin matrix.
The multi-layer fabrics were woven by pitch-based carbon fiber rovings.
Then the relationship between structure of multi-layer fabric and mechanical properties of the coposites were investigated.
The Mechanical properties were measured by tensile and flexural test.
The properties were compared with those of laminated fabric compasites. The results are summarized as follows;
1) The tensile strength and the tensile modulus of multi-layer fabric composites tend to decrease with increase in the angle of fiber orientation of composites.
2) The tensile strength and the tensile modulus of multi-layer fabric composites were lower than those of laminated fabric composites: it was the slight difference.
3) The flexural strength of composites wasn't influenced by thestructure of fabric weave.
4) The flexural modulus of composites was clearly influenced by the structure of fabric weave. The flexural modulus of multi-layer fabric composites was maximum 1.5 times those of laminated fabric composites.
5) From the flexural test of the multi-layer fabric composites: compression fracture was observed at the upper surface when the middle level flexural load was measured, then tensile fracture was observed at the lower surface over the maximumload.

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Pore volume and macropore-size distribution of charcoal produced from the wood of a wide variety of trees were measured by mercury intrusion porosimetry and the following results were obtained.
The shape of the distribution curve was remarkably dependent on wood type. Total pore volume of charcoal produced by carbonizing at high temperature was less than that of charcoal produced by carbonizing at low temperature. Total pore volume of coniferous tree charcoal exceeded that of broad-leaf tree charcoal. Total pore volume of molding charcoal wassmall, eventhough it came from the coniferous tree. Total pore volume of coconut shell charcoal and Kashioak charcoal was small, since these charcoal types are hard. The distribution curves of coconut shell, coconut shell charcoal, and coconut shell activated carbon were resemble, but the pore volume of the coconut shell was smaller than the others. Total pore volume increased in proportion to that of large pores.

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In order to shorten the processing time for oxidative stabilization in pitch based carbon fiber, petroleum derived mesophase pitch fiber was oxidized in air containing 2% of NO₂. Oxygen consumption by pitch fiber were determined under several conditions by measuring O₂ concentration of exit gas from the reactor. The change of elemental composition ofoxidized pitch fiber was elucidated with elemental analysis. Large shortening of required time for complete stabilization by NO₂ addition was quantitatively demonstrated. The elementalanalysis of oxidized fiber indicated that the higher rate of oxygen fixation in the fiber is considered to responsible for shortening the required time for complete stabilization.

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Mesophase pitch-based carbon fibers (MPCF) have been prepared by a melt-brow method and applied to Li ion secondary battery. To improve the reversible capacity, B was doped to the fiber about 1 at % by adding B₄C to the pre-carbonized milled fibers and then heat-treated up to 3000°C in Ar. The structure of B-doped fibers was characterized and compared with that of non-doped standard fibers, and also anode performances for Li ion battery were evaluated. The capacity of B-doped fibers was 340 mAh/g, while the non-doped fiber showed 300 mAh/g. The voltammograms of both fibers were different from each other. The mechanism of anode reaction is discussed based on the unique structure of B-doped fibers. It is suggested that B doping to the MPCF is very effective for the anode performance.

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We tried to produce activated carbons with high specific surface area from bean-curd refuse by chemical activation using several alkali metal compounds such as K₂CO₃, NaOH and Na₂CO₃, and H₃PO₄ as the reagent. The effects of carbonization temperature, holding time and impregnation ratio of reagent to dried bean-curd refuse on pore structure of the activated carbons produced were investigated.
Among the chemicals tested K₂CO₃ is found to be the most effective as the impregnation reagent. In a range of carbonization temperature above 700°C, the specific surface area of the activated carbon produced increases rapidly, takes a maximum at a carbonization temperature of about 800°C and decreases with further increase in temperature above 800°C The specific surface area attains a maximum at a holding time of about 60 min. The specific surface area increases with increasing impregnation ratio up to an impregnation ratio of 1.00, beyond which it gradually decreases with further increase in the impregnation ratio. The specific surface area of activated carbon produced under the suitable conditions from the bean-curd refuse impregnated with K₂CO₃ is as high as 2656m2/g.
It is found that K₂CO₃ changes the carbonization behavior of the bean-curd refuse in a range of lower temperature below 400°C and reacts further with the carbonized material to increase the specific surface area in a range of higher temperature above 600°C.

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Polymerization of methyl methacrylate (MMA) was carried out in the presence of exfoliated graphite in water. Exfoliated graphite encapsulated with poly (methyl methacrylate) (PMMA) was obtained. The amount of PMMA in the encapsulated exfoliated graphite can be controlled by changing the ratio of the monomer to exfoliated graphite. SEM and TEM observation indicates that the exfoliated graphite is coated homogeneously by PMMA.
This encapsulated exfoliated graphite composite can be directly molded by hot press. The electric conductivity and the shielding effect for electromagnetic interference of this molded product were superior to those of the exfoliated graphite-PMMA composite made by mechanical mixing.
The microscopic observation of the cross section of the specimen shows that the difference of electric conductivity between the encapsulated exfoliated graphite-PMMA composite and the mechanically mixed exfoliated grapite-PMMA composite and the mechanically mixied exfoliated graphite-PMMA composite is due to the degree of dispersion of exfoliated graphite in polymer matrix, i.e., the exfoliated graphite in the encapsulated composite is homogeneously dispersed in comparison with that in the mechanically mixed composite.

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Diamond-like carbon (DLC) thin film deposition was examined by applying 13.56 MHz of r.f. power to the substrate electrode. We tried to control deposition temperature by the plasma pulse deposition technique: repeated cycles of alternating 5 s of deposition with 180 s of cooling, then we investigated the influence of the deposition temperature on the thin film characteristics and structure in details.
It is found that the deposition temperature plays a more significant role than the self-bias potential which is up to now considered as an important parameter. Our results suggest that the surface structure of the film after ion impacted rather than ion impact energies dominates the characteristics and structure determination. Definitely, the deposition temperature is closely related to the mobility of the fragments generated by the ion bombardments and the migration of radical and neutral species adsorbed on the film surface. Moreover, the deposition temperature is concerned in the promotion of the dehydrogenation of the film.
As the model for DLC film structure, we suppose that the three dimensional random network structure is developed mainly, and the condensed aromatic ring structures as precursors of the carbon cluster and the small graphite-like carbon clusters are slightly mixed into the random network structure.

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Two activated carbon fibers supporting MnO particles (0.84wt% Mn and 1380m²g^-1, 11.84wt% Mn and 2050m²g^-1) were prepared from phenolic resins containing manganese acetate tetrahydrate and their deodorization abilities against H2S gas were examined. The former fiber contained the finely dispersed MnO particles and exhibited a high deodorization ability which is resulted from both a high specific surface area and the supported fine MnO particles. The ability of the latter fiber was not so high in spite of having a large surface area supporting a larger amount of MnO, because the large MnO particles deposited in the activated carbon fiber and on its surface abundantly. It was revealed that a high quality deodorant activated carbon fiber against H2S gas is prepared by supporting the fine MnO particles on the micropore surface more abundantly.

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It is known that dissolved carbon in the molten Iron (Fe) crystalizes out as graphite on cooling. Graphite-encapusulated Fe sphere was prepared by using this process.Mixture of carbon black and 45 atm % Fe powder was heat-treated at 2500°C and then the magnetic product was separated from the residure. The product was α-Fe sphere wrapped in graphite. The sphere was 0.25-100 μm in diameter and contained 92 wt % of Fe. The thermogravimetric analysis of the sphere in oxidative atmosphere showed thata weight loss sets in at 730°C, as well as a natural graphite. Magnetization curve did not exhibit the hysteresis loop and saturation magnetization was 189emu/g corresponding to Fe content. From those results, it was concluded that the graphite-encapsulated Fe sphere is ferromagnetic and stable in oxidative atmosphere.

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In the present paper, various kinds of carbon fibers were studied in order to cover a wide range of crystallinity from disordered to highly graphitized materials. Poly-p-phenylene (PPP)-based granular carbon was also comparatively chosen as one of the highly disordered carbons against low crystalline carbon fibers. The discharge capacity of carbon fiber electrode was shown to depend on the crystallite thickness Lc₀₀₂. Disordered and well-ordered carbon fibers had larger capacity than those with intermediate crystalline thickness. Milled mesophase pitch-based carbon fibers (MPCF) showed the highest capacity in fibers with high crystallinity, which seemed to be applicable for practical cell. 1 at % B-doped mesophase pitch-based carbon fiber indicated improvement in crystallite thickness and discharge capacity. It was suggested in the present paper that the crystallite thickness of carbon electrode is one of the most important factor for design of Li ion battery. Furthermore well controlled mesophase pitch-based carbon fibers as well as B-doped one are very promissing for the practical application for Li ion battery.

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