Potassium-graphite intercalation compounds with 7 different compositions ranging from KC₃₀₀ to KC₂₄ were prepared from exfoliated graphite sheet (Grafoil). Resistivity, magnetoresistance and hydrogen-sorption capacity of these compounds were determined. KC₃₀₀ and KC₂₅₀ showed semi-conductive temperature dependence of the resistivity as well as host Grafoil, while KC₁₆₈ and more rich compounds showed metallic behavior. Dependence of the resistivity and magnetoresistance on the potassium concentration was divided into two regions with a critical concentration at about KC_60-70. Both of these properties decreased considerably with increasing potassium concentration below this critical concentration, and then became almost constant above it. A remarkable correlation between transport properties and hydrogen-sorption capacity was suggested.

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Calcination of an ytterbium-O-phenylene hybrid copolymer under an argon atmosphere gave material composed of nanosized Yb₂O₃ particles and carbon clusters. ESR spectral examinations showed that material had a photo-responsive oxidationreduction function though an electron transfer from Yb₂O₃ particles to carbon clusters.

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A tellurium-S-phenylene-O-strontium-O-phenylene-S hybrid copolymer was calcined under an argon atmosphere at 400-600°C. The material calcined at 500°C was found to be composed of nano-sized SrS and Te particles in the matrix of carbon clusters. ESR spectral examinations revealed that the calcined material has a photoresponsive oxidation-reduction function through an electron transport from carbon cluster to metal compound.

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The intercalation of aluminum halides into graphite in the presence of halogens is investigated. The vapour pressure of aluminum halides as intercalates and that of halogens as additives were well-controlled to be same in order to compare their reactivities. The order of reactivity for intercalates was found to be AlCl₃>AlBr₃>All₃. The activity of halogen additives was also revealed to be in the following order: Cl₂>Br₂>I₂.

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Fifty wt % of multiwall carbon nanotube (MWCNT) was blended with a conventional rubber compound to examine its effect on mechanical properties of the resulting composite, through the comparison with carbon black N234 and MWCNT/carbon black N234 (1/1) mixture as references. MWCNT resulted in a significant increase of elastic modulus, compared with N234. It was revealed from microscopic surface analysis that a low dispersion of MWCNT in the rubber matrix was one of the causes of this favourable effect. The low dispersion of MWCNT, oppositely, brought about lower fracture elongation and fracture strength than in the case of N234. The MWCNT/N234 mixture showed just intermediate effects between MWCNT and N234.

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Preparation and characterization of various intercalation compounds of graphite oxide were summarized. The hydroxyl groups with acidic nature in graphite oxide were responsible for the intercalation of various reagents including alkyltrimethylammonium ions, alkylamines and silylating reagents. The size of the empty space in the interlayer spacing of the resulting intercalation compounds varied in a wide range by changing the kind or amounts of intercalated species. They possessed hydrophobic nature, therefore, large amounts of organic molecules such as pyrene were adsorbed from water based solution onto them. In addition to this, the intercalation compounds with long alkyl chains were soluble in organic solvents, forming so called nanosheet solution. This enabled to prepare thin film samples by casting the solution containing intercalation compounds and they can include various organic dyes between the alkyl chains. These alkyl chains well prevented the aggregation of dye molecules introduced into the layer of intercalation compounds. The fluorescence from organic dyes included in them increased by introducing perfluoroalkyl chains into them instead of alkyl chains.

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