Abstract:

In order to study the effect of graphene addition and different preoxidation conditions on the structure of pre-oxidized fibers and carbon nanofibers, polyacrylonitrile (PAN) nanofibers were prepared by electrospinning, And then carbon nanodibers were obtained by preoxidation and carbonization. Finally, the structural change of pre-oxidized fibers and carbon nanofibers were characterized by Foruier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry, Raman spectrometer and scanning electron microscopy. The reaults show that a stable trapezoidal structure is formed by the dehydrogenation, cyclization and oxedization reactions of PAN molceules during the prioxidation process. The relative cyclization rate, aromatization index and degree of cyclization of PAN fibers gradually increase with the rise of preoxidation temperature. The addintion of graphene improves the graphitization degree of carbon nanodibers and has a certain inhibition effect on the dehydrogenation and  cyclization reaction. Thererfore, the fracture degree of carbon nanofibers reduces. When the preoxidation temperature is 260?C, a mew structure of the fibers is substantially formed.

Key words: polyacrylonitrile, graphene, electrospinning, preoxidation treatment, carbonization