Mamoru Senna¹, Chika Takai², Masayoshi Fuji³

¹Faculty of Science and Technology, Keio University, Hiyoshi, Yokohama, 223-8522, Japan
²Faculty of Engineering, Gifu University, Yanagido, Gifu, 501-1193, Japan
³Advanced Ceramics Research Center, Nagoya Institute of Technology, Honmachi, Tajimi, 507-0033, Japan

Mechanochemical treatment of solid carbohydrates or hydrocarbon, such as cellulose or paraffin wax with metal oxide nanoparticles brings about numerous functional nanocomposites. They are combined with sustainable materials via affordable chemical processes. Starting from physicochemical basics of mechanochemical reactions at the boundaries between carbohydrates or hydrocarbon and metal oxides, case studies are given on the changes in the microstructural properties of cellulosic compounds (SSC) with TiO₂ or its hydrates by milling SSC with aqueous precursors of TiO₂ or TiO₂ nanoparticles. Discussion will be concentrated on the non-covalent chemical interaction between SSC and TiO₂ with and without the aid of surrounding polarized water molecules. Simultaneous micronization of SSC structural units and changes in the properties of composites upon subsequent heating are also discussed, in conjunction with the drying condition of the wet complex mass. Despite its basic science oriented experimental works, the authors also try to discuss some unique photo response of titania in the nanocomposite. When time permits, mechanochemical reduction of a stable oxide, V₂O₅, with paraffin wax to VO₂ is referred. Stabilization of thermodynamically less stable VO₂ by oxygen vacancies introduced during co-milling with paraffin wax will also be explained, together with a possibility of applying to latent heat energy storage devices.