New processing method for tungsten carbide nano-crystalline particles and nano structural carbon via polyacrylonitrile gasification

A simple processing route has been developed for a nano-sized crystalline tungsten mono-carbide (WC) and a novel nano-structural carbon materials. Starting materials for WC synthesis were selected tungstic acid (H2WO4) and polyacrylonitrile (PAN) powders. The starting powders were heat-treated at 1200 degrees C for 30 min with a nitorgen gas flow in an alumina tube. The acquired WC powder had a nano-sized crystalline and high-specific surface area (26.0m(2) g(-1)). Crystallite diameter size was estimated to less than 20 nm. Compared with theoretical value, approximately 2.0 mass % of free carbon was measured in the prepared WC. It was observed that layered graphitic carbon was formed around the WC particles. If the graphitic carbon is separated from the WC particles by appropriate techniques or processing conditions, these techniques using PAN as a carbon source may have possibility for processing not only WC but also nano-structural carbon materials such as graphene. (C) 2014 The Ceramic Society of Japan. All rights reserved.