Porous ultrafine fibers via a salt-induced electrospinning method

A salt-induced electrospinning method to produce porous polymer ultrafine fibers was reported in this work. Scanning electron microscopy, energy dispersive spectrometer, and BET surface area measurement were employed to evaluate the morphology, the element distribution, and the surface area of fibers, respectively. According to the investigation result, pores on the fiber were induced by water-soluble salt during electrospinning process in a humid spinning environment. There was no porous structure on the fiber surface when water-insoluble salt was used in a wet electrospinning environment or when water-soluble salt was used in a dry electrospinning environment. Compared with pure fibers, the average surface area of fibers containing salt increased significantly due to the porous structure. The possible mechanism of the porous structure induced by salt was proposed. Water-solubility salt and humid environment were considered as the key roles in the formation of porous structure. This method provided a new way to form porous structure during electrospinning.