Surface modification of carbon fibers by anodic oxidation and its effect on adhesion

PAN-based high strength carbon fibers were electrochemically treated in an ammonium hydroxide electrolyte for the increasing of surface functional groups on fiber surfaces, resulting in enhancing fiber-matrix adhesion of the composites. According to the FT-IR and XPS measurements, it revealed that the surface functional groups on fibers induced by electrochemical treatment were largely dominated in the mechanical interfacial properties of composites, i.e., the interlaminar shear strength (ILSS). Also, a good correlation between (O_1s+N_1s)/C_1s and ILSS was established and found that the 5 A.m^-2 current density was the optimum condition for this system.