Appearance of edges of miniaturized carbon fibers prepared by electrochemical processing and their evaluation

Exfoliated carbon fibers (ExCFs) of PAN- and pitch-based carbon fibers prepared by electrochemical processing followed by a rapid heat treatment have a large amount of edges because they have gone through the formation of graphite oxide and fragmentation. This is seldom observed in carbon nanotubes. This was clarified by the analysis of thermal programmed desorption and temperature programmed oxidation of the ExCFs. Carboxyl groups were generated at the edges by electrochemical processing. Subsequently the number of carboxyl groups decreased as a result of the rapid heat treatment, while the number of oxygen functional groups derived from CO increased. The differences in morphology of ExCFs prepared from PAN- and pitch-based carbon fibers seem to reflect the texture of the initial carbon fibers.[TANSO 2012 (No. 255), 245–253]