Hydrogen storage properties of the ball-milled mixtures composed of hydrogenated nano-structural graphite (C^nanoH_x) and lithium hydride (LiH) were examined from thermodynamic and structural points of view, where the C^nanoH_x was synthesized by ball-milling graphite powder under hydrogen atmosphere. Since hydrogen atoms in the C^nanoH_x and LiH are strongly bonded with each host atom, heating up to >600°C is necessary to release hydrogen from each solid product. The C^nanoH_x and LiH composites desorbed hydrogen and hydrocarbon gases below 400°C with about 9.4 mass% weight loss. The 2: 1 composite of the C^nanoH_x and LiH reversibly stored hydrogen with an effective capacity of about 4.5 mass % at 350°C. No evident peaks were observed in XRD profiles after the dehydrogenation, indicating that the nano-structural feature remained after dehydrogenation due to formation of (CLi) ^nano clusters. However, only the LiH phase was crystallized after rehydrogenation at 350°C. From these results, it is concluded that hydrogen in the composites is destabilized by a novel interaction between the C^nanoH_x and LiH in a nanometer scale, and is desorbed at lower temperatures than each of the components. Therefore, this Li-C-H system can be recognized to be a new family of hydrogen storage materials.

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With the precursors prepared from saccharides, such as glucose and cellulose, and boric acid, microcrystals of boron carbides were synthesized at relatively low temperatures of 1500-1600°C by 1 h treatment in an argon atmosphere. Hydrothermal treatment at the stage of precursor preparation was found to be effective to form the precursors which readily decompose to boron carbides in the shape of micrometer-sized crystals. Although a small amount of free carbon is contained in the products and substituted-type boron carbides may be included, this process is interesting: precursor preparation is very simple and the raw materials are inexpensive, above all the process is not hazardous.

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The effect of stereoregularity of poly (acrylonitrile) (PAN) on the stabilization mechanism was investigated by TG/DTA measurements, Infra-red spectroscopy, and gas chromatography-mass spectroscopy (GC-MS). The stabilization of atactic PAN (at-PAN) with lower stereoregularity occurred at a lower temperature than that of isotactic PAN (iso-PAN) with higher stereoregularity. The weight loss during stabilization was derived from the evolution of ammonia, hydrogen cyanide and compounds related with nitrile groups, having molecular weights between 41 and 147, formed by the bond cleavage reactions of PAN. The amount of gases evolved from iso-PAN was greater than that from at-PAN. These results revealed that the stabilization reactions proceeded more steadily in at-PAN than in iso-PAN. However, the IR spectra of the PAN samples with different stereoregularities recorded at the initial stage of the stabilization revealed significant differences in their chemical structures. The initial stage of the stabilization reaction in at-PAN occurred preferentially at the disordered chain configuration. However, the stereoregularity of iso-PAN stayed constant during the initial stage of stabilization reaction, showing that there exists no selectivity of the reactive site as opposed to at-PAN. No difference in the chemical structure could be found after the stabilization of at-PAN and iso-PAN.

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From magnesium citrate and its mixtures with poly (vinyl alcohol), mesoporous carbons were successfully obtained through their carbonization at 900°C, followed by the dissolution of MgO. A high surface area as more than 1500m²/g was obtained without any activation process, which was mainly due to mesopores with a size of about 5 nm, and mesopore volume reached 2 mL/g. Electric double layer capacitor composed of these mesoporous carbons and 1 mol/L H₂SO₄ electrolyte showed a high capacitance about 320 F/g with a charge-discharge current density of 20 mA/g and about 220 F/g with a high current density of 1000 mA/g. The carbons prepared showed a high adsorption ability for gasoline vapor, about 1g/g of carbon. A relatively good linear relation between adsorbed amount of gasoline vapor and pore volume with the size less than 10 nm was found.

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The textural characteristics and surface chemistry were inspected for activated carbons (AC) prepared from cattle-manure-compost (CMC) by ZnCl₂ activation at 400°C for 1 h. Methylene blue (MB) adsorption in aqueous phase onto the prepared AC was conducted to examine the potential capability as water treatment adsorbents in practical use. Furthermore outgassings in helium flow at 400°C and 900°C were performed to check the changes in carbon properties. N₂ adsorptiondesorption, elemental analysis, pH of the point of zero charge (pH_pzc) measurement and Boehm titration were employed for characterization. The prepared AC's exhibited excellent performance for MB adsorption due to their wide surface, large mesopore volume and high nitrogen content. It was also clarified that the out-gassing treatment at 400°C little influence on the pore structure but significantly changed the surface chemical properties such as oxygen functional groups and pHpzc. The kinetics and capacity of MB adsorption were controlled by both bulk structure including surface area and pore distribution and surface chemistry of the graphene layer.

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The silicon-containing thermosetting polymer, poly [(phenylsilylene) ethynylene-1, 3-phenyleneethynylene] (abbreviated as MSP), was hybridized with metal oxides, such as SiO₂, TiO₂, Al₂O₃ or B₂O₃ by a blending and sol-gel methods. Amorphous silicon containing carbon obtained by pyrolyzing MSP at 1000°C showed higher oxidation-resistance than the commercial amorphous carbon. The carbon-silicon-B₂O₃ hybrids (B₂O₃ 8%) obtained by pyrolyzing the molding sample of MSP/B₂O₃ at 1000°C showed much higher oxidation-resistance than the carbon derived from MSP.

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Several aspects of sorption behavior of alkali metal-graphite intercalation compounds were described. Dependence of hydrogen-sorption capacity of potassium-graphite intercalation compounds (K-GICs) on the potassium concentration of KGICs was found to be analogous to those of resistivity and conduction electron spin resonance (CESR) g-value of the K-GICs. Host effect on the hydrogen-sorption behavior of CsC₂₄ was also described. The saturated amount of sorption increased with heat-treatment temperature (HTT) of the host carbons. It was confirmed that H2 was able to be sorbed even for CsC₂₄ prepared from less graphitized carbons such as HTT-1300. The change of electrical resistivity (conductivity) and CESR spectra of alkali metal-graphite intercalation compounds (AM-GICs) during sorption of ammonia was also described.

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