Synthesis of nanometre silicon carbide whiskers from binary carbonaceous silica aerogels

A novel synthesis process, based on a carbothermal reduction reaction of binary carbonaceous silica aerogels, has been developed for producing nanometre silicon carbide whiskers. The process uses binary carbonaceous silica aerogels as precursors. The precursors, which are derived from carbonaceous sol and silica sol. are prepared by sol-gel supercritical fluid drying and provide a high contact area of reactants. The homogeneous distribution of silica within carbon and their loose structure result in the formation of purer nanometre silicon carbide whiskers. The precursors and their carbothermal reduction products are investigated by TEM, EDX and XRD analysts. The effect of heat-treatment temperature on the production of SIC whiskers is discussed. (C) 2001 Elsevier Science Ltd. All rights reserved.