Studies on the Surface Properties of Oxidized Carbon Fibres

The surface properties of carbon fibres, which were oxidized or not, were studied by Inverse Gas Chromatography, electrobalance, and ESCA. IGC experiments were done using carbon fibres as adsorbent and n-alkane as probe. Obtained adsorption isotherms belong to type 2 of Brunauer classification and the specific surface area of carbon fibres is increased by oxidization.The contact angles of formamide on the carbon fibres under n-alkane were measured by means of electrobalance and the surface free energy and its components of the fibres were obtained. The fraction of polarity part of surface free energy is increased by oxidization.It was known from ESCA that the value of O/C is increased after oxidization, but the influence is only on the surface. 5 nm beneath the surface, oxidization had no influence to the ratio of O/C.