Effects of ethanol and isopropanol on the structures and properties of polyethersulfone/perfluorosulfonic acid nanofibers fabricated via electrospinning

摘要

Blend solutions of polyethersulfone (PES) and perfluorosulfonic acid (PFSA) resin were fabricated into nanofibers via electrospinning. Ethanol (EtOH) and isopro-panol (IPA) were employed to investigate the effects of non-solvent (NS) on the structures and properties of the electro-spun PES/PFSA nanofibers. Average diameters of the elec-trospun nanofibers increased with NS content while the water contact angles of the nanofiber membranes decreased. Although all the nanofiber membranes presented strong hydrophobicity initially, the water contact angle would drop to less than 90° within 30 min. Energy dispersive X-ray spectrums (EDS) showed that the nanofibers electrospun from solutions with more NS presented higher sodium content on the surface because more-SO _3Na groups were on the external plane. N _2 adsorption-desorption measurement revealed that increase of NS content in the solvent mixtures resulted in nanofibers with surface area much bigger in experiment than that in calculation, which meant rough structures occurred on the surface of electrospun nanofibers. These rough structures were beneficial to improve the fric-tional resistance between nanofibers and therefore enhanced the break strength and Young's modulus of the nanofiber membranes.