SCANNING-TUNNELING-MICROSCOPY STUDY OF ACTIVATED CARBON-FIBERS

Scanning tunnelling microscopy (STM) has been used to study isotropic pitch-based carbon fibres before and after steam activation. The resul ts show that the present carbon fibre precursor exhibits a particulate surface which is very favourable for the formation of activated carbo n fibre. After activation, the carbon fibre surface becomes much more porous and rougher, and the mesopores are evidently present on the sur face. Because the scale is down to atomic resolution, the STM observat ions offer direct evidence for the existence of micropores on the surf ace of the activated carbon fibres. In addition, the surface textures of both fibres are presented and discussed.