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

Abstract

Blend solutions of polyethersulfone (PES) and perfluorosulfonic acid (PFSA) resin were fabricated into nanofibers via electrospinning. Ethanol (EtOH) and isopropanol (IPA) were employed to investigate the effects of nonsolvent (NS) on the structures and properties of the electrospun PES/PFSA nanofibers. Average diameters of the electrospun 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 3 Na 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 frictional resistance between nanofibers and therefore enhanced the break strength and Young's modulus of the nanofiber membranes.

De Novo Ion-Exchange Membranes Based on Nanofibers

“…The PFSA/PVA NF mats exhibited good catalytic activity in ethyl acetate synthesis, with an efficiency proportional to the specific surface area of the NFs mats. The addition of the non-solvent to the electrospinning solution further improved the utilization of sulfonic acid groups in PFSA molecules [ 47 ]. Moreover, addition of nanoparticles [ 48 , 49 ] also improved the density of surface acid sites.…”

Nanofibers as novel platform for high‐functional ion exchangers

“…However, it is difficult to obtain nanofibers by the electrospinning of Nafion solutions due to the low solution viscosities resulting from the poor entanglement of the polymer chains and the presence of aggregates in the solution due to ionic interactions . To solve this problem, it has been common to add small amounts of spinning aids, such as poly( N ‐vinyl pyrrolidone), poly(ethylene oxide), poly(acrylic acid), poly(vinyl alcohol), poly(ethersulfone), and poly(acrylonitrile), to the Nafion solutions to increase the polymer chain entanglement or to suppress the aggregation formation. Subianto et al reported that the threshold concentration of poly(ethylene oxide) for fiber formation depends on both the molecular weight of poly(ethylene oxide) and the concentration of the perfluorosulfonic acid ionomers .…”

Improvement of CO2/CH4 separation characteristics of polyethersulfone by modifying with polydimethylsiloxane and nano-silica

“…PES also exhibits high mechanical strength, thermo-stability and stability against chemicals [4] which make it very good candidate for fabrication of gas separation membranes [5][6][7]. Several studies have focused on modification of PES membranes to expand its applications in gas separation industries.…”