X-ray photoelectron-spectroscopic studies of carbon-fibre surfaces. Part 5.—The effect of pH on surface oxidation

Abstract

Carbon fibres, electrochemically treated in a variety of different electrolytes, have been analysed using X.p.s. and s.e.m. The amount and type of surface oxide varies considerably depending upon the pH of the electrolyte. Much more surface is produced in acidic environments. Carbon dioxide is evolved during treatment in acidic environments, and oxygen, together with clouding of the solution, in basic environments. Different oxidation mechanisms are suggested at different pH values.