Ultrafiltration membranes with tunable morphology and performance prepared by blending quaternized cardo poly(arylene ether sulfone)s ionomers with polysulfone

The original quaternized cardo poly(arylene ether sulfone)s (QPES-I) ionomers was employed as the virgin polyelectrolyte and its counterions (I − ) were exchanged with F − and PF 6 − to prepare QPES with different anions(QPES-X, X   =   F, PF 6 ), then QPES-X/PSF blended ultrafiltration membranes was prepared by the nonsolvent induced phase inversion process. Scanning electron microscopy (SEM) was used to characterize the cross section morphology and surface morphology of blended membranes, and atom force microscopy (AFM) was employed for obtaining the three-dimensional images of QPES-X/PSF blended membranes, respectively. The surface chemical composition of the asymmetric membrane was investigated by X-ray photoelectron spectroscopy (XPS). Under similar preparation conditions, the water contact angle on membrane surface increased in the order of QPES-F   <   QPES-I   <   PSF   <   QPES-PF 6 , while the pure water flux of the membranes decreased with that order. The results revealed that the surface and cross section morphology, surface roughness, QPES-X content on membrane surface, as well as the hydrophilicity and performance of blended membranes were closely related to the counterions of QPES-X. Membrane prepared with QPES-F is hydrophilic and possesses outstanding performance among all the investigated materials, demonstrating a water flux of 2163   L   m −2   h −1 and BSA rejection of 93% at an 18   wt% polymer concentration and 15% QPES-F content. Antimicrobial activity studies demonstrate that the blended membrane having 15% QPES-F possess a sterilization rate of 73% towards E . coli .