Fabrication of Core-Sheath Fibers by Electrospinning for the Formation of Flexible Carbon Nanofibers

摘要

Carbon nanofiber is a promising material for several applications such as advanced catalyst support, adsorbent and filtration. In this work, carbon nanofibers were formed by the pyrolysis of polyacrylonitrile (PAN)/poly vinyl pyrolidone (PVP) core-sheath nanofibers, which were fabricated by co-axial electrospinning technique. The presence of PAN, which degraded at higher temperature than PVP, could provide flexibility to the final carbon nanofibers. For the fabrication of the core-sheath nanofibers, solution of PAN and solution of PVP, both in dimethyl formamide (DMF), were supplied separately to a co-axial nozzle. The concentration of the polymer was varied in the range of 6-10% wt. Upon the application of high electrical potential in the range of 15-18 kV, the solutions were ejected from the nozzle and deposited on the grounded collector set the distance of 12-18 cm from the nozzle. The products were analyzed by scanning electron microscope (SEM) and transmission electron microscope (TEM). It was found that concentration of both PAN and PVP in the solutions, the applied potential and the distance from the nozzle to the collector affected morphology and size of the product. In general, the average diameter of the fibers increased with the increase in polymer concentration of the spinning solutions.