Modification of carbon fiber surfaces by electrochemical reduction of aryl diazonium salts: Application to carbon epoxy composites

Electrochemical reduction of aryl diazonium salts on carbon fibers both in aprotic and in aqueous acidic solutions leads to the grafting of the aryl group on the carbon surfaces. In acidic medium the grafting of 4-nitrophenyl groups occurs simultaneously with the reduction to 4-aminophenyl groups which, in their turn, can react with the epoxy functions of epoxy resins. It is shown through a simple mechanical test that this process increases the adherence between the fiber and the matrix. (C) 1997 Published by Elsevier Science Ltd.