Surface properties of PAN-based carbon fibers tuned by anodic oxidation indifferent alkaline electrolyte systems

High modulus carbon fibers were anodic oxidized in various alkaline electro lyte systems. The success of the modification was proved by contact angle m easurements. The fiber surface tension was calculated from the measured con tact angles using the harmonic mean method. With the exception of one elect rolyte system, all in alkaline electrolytes modified carbon fibers showed a n increased fiber surface tension. The increased fiber surface tension is d ue to the increased number of oxygen containing surface groups detected by energy dispersive X-ray microanalysis (EDX). Anodic oxidation causes a roug hening of the fiber surfaces observed by scanning electron microscopy (SEM) . Cyclo-voltammetric investigations give an possible mechanism of the anodi c oxidation in alkaline electrolytes. (C) 1999 Elsevier Science B.V. All ri ghts reserved.