Beneficial effect of multi-wall carbon nanotubes on the graphitization of polyacrylonitrile (PAN) coating

Abstract

Polyacrylonitrile (PAN) solutions were deposited on quartz plates by spin coating to yield 2-3 ?m thick PAN films. The films were decomposed at 1000?C in N2 atmosphere into electrically conducting carbonaceous coatings. When the precursor solution contained cobalt (0.2 g Co-acetate per 1 g PAN) and/or multi-wall carbon nanotubes (MWCNTs, 2 mg MWCNT per 1 g PAN) the specific electrical resistance of the product film dropped from the original 492 ??cm-1 value down to 46 ??cm-1. By excluding all other possibilities we came to the conclusion that the beneficial effect of carbon nanotubes is related to their catalytic action in the final graphitization of condensed nitrogen-containing rings into graphitic nanocrystallites.