Abstract
Recently, new porous carbon materials have been developed utilizing the natural porousstructures of some plant matters. The carbon materials are manufactured by mixing with a phenol resin, pressure forming, drying, and then carbonizing at 900°C. The authors have been studied the carbon material made from the defatted rice bran (RB carbon). However, the RB carbon includes some deliquescent components, and therefore has large hygroscopic expansion and large reduction of the mechanical strengths under wet and aquatic conditions. The low water resistance is associated with the inorganic components of P and K in the rice bran. In contrast, the rice hull does not contain such inorganic components. In this study, the authors proposed the production of the water-resistant rice-hull silica carbon (RHS carbon) from the rice hull and the correcting methods of the low water resistance for the RB carbon. The RHS carbon has low hygroscopic expansion and no reduction of the compressive strengths under aquatic conditions.
