Preparation of Polyacrylonitrile Nanofibers with Controlled Morphology Using a Constant-Current Electrospinning System for Filter Applications

Polyacrylonitrile (PAN) fibers with average diameters in the range 100 nm with beaded morphology were prepared by a constant current electrospinning system. The fiber morphology could be easily varied by controlling the flow rate and electric current during the electrospinning process without changing the precursor solution. It was found that the use of lower flow rates resulted in more beaded fibers while the number of beads increases. The electric current could control the fiber morphology in which the beaded number (the number of beads or the beaded fibers) decreased as the electric current increased. It was also found that diameter and length of the beaded fibers increases as the electric current increases. Therefore, these results are able to be applied to find optimal conditions in obtaining high performance filter media.