Carbonization mechanism of polyacrylonitrile under existing metal particles

Nickel particles impregnated polacrylonitrile (PAN) was prepared by gelation/crystallization method and pyrolyzed under argon atmosphere between 800°C and 1625°C. In order to investigated the heat-treatment temperature (HTT) effect on the morphology of nickel particles, the three-layered film were obtained by inserting PAN/Ni layer between PAN gel layers. The morphology of the carbonized films was observed by scanning electron microscopy. The graphitization degree was analyzed on the basis of X-ray diffraction intensity distribution from the (002) plane. The experiment data suggest that nickel particles during the graphitization experienced formless shape, cubic shape and round shape from low temperature to high temperature; especially, there is hexagonal trance on the surface of round shape. The electrical conductivity of 1600°C-treated film could reach 66.9 S/cm and the thermal stability is high.