Microwave plasma treatment effect on the surface energy of carbon fibres

Abstract

The influence microwave (2.4 GHz) plasma treatment duration (under reduced pressure of air or argon 1-2 Torr) on the surface properties of various carbon fibres (M 40, T 300 (Toray)) has been investigated. The dispersive ( gamma SD) and polar ( gamma SP) component of their surface energy were determined by a micro-gravimetric indirect method of wetting contact angle measurements within two liquids. Even for very short treatment durations (2-5 s) important increases in gamma SP up to 20-30 mJm-2 are obtained (under air and under argon) while gamma SD display an opposite evolution. The changes in surface topography as revealed by SEM were also considered.