Effect of various treatments on carbon fiber surfaces studied by Raman microprobe spectrometry

High-modulus and high-strength carbon fibers were submitted to oxidation plus sizing and grinding treatments, Subsequent changes at the fiber surfaces were studied by Raman spectrometry, X-ray diffractograms and Raman spectra of the fresh fibers were compared with those of other carbon materials with different graphitization degrees. The industrial oxidation+sizing treatment induces disorder at the fibers surface, this being of a higher order of magnitude than that introduced by grinding. However, this disorder is different in nature from the intrinsic disorder typical for little graphitized carbon materials.