Preparation and characterization of graphene-reinforced polyacrylonitrile-based carbon nanofibers

Graphene was obtained by vacuum-assisted thermal expansion of graphite oxide followed by a further thermal annealing. A series of polyacrynitrile (PAN)-based nanofibers with different graphene contents were prepared by electrospinning, using the graphene as the reinforcement. SEM, XRD, FT-IR, TG-DSC and elemental analysis were used to investigate the microstructure evolution of the PAN nanofibers during stabilization and carbonization. Results show that the addition of graphene improves the orientation of the PAN molecules, but decreases their crystallinity. This inhibits oxidation, cyclization and dehydrogenation during the oxidative stabilization of PAN fibers. Graphene acts as nucleation sites for the growth of graphite crystals along the graphene plane during carbonization.