The Surface Characterization of Polyacrylonitrile-based Carbon Fibres by Electrochemical Techniques

Abstract

Carbon fibre surface properties have been studied by measuring the electrochemical behaviour of the hexacyano ferrate (III)/ferrate(II) couple using carbon fibre brush electrodes. Courtaulds Grafil polyacrylonitrile (PAN) based fibres have been studied that have been subjected to different extents of a proprietary wet oxidative surface treatment varying from 0 to 500% of the standard treatment. Analysis of the cyclic voltammograms gives information on the electroactive surface area, a parameter related to the conductivity perpendicular to the fibre surface and rate of electron transfer across the surface of the fibres. The electrochemical data are correlated with other surface properties such as the surface area determined by oxygen chemisorption, surface energy components and some adhesion parameters, such as interlaminar shear strength and critical fragment aspect ratio of epoxy matrix composites.