High flux nanofiltration membranes based on layer-by-layer assembly modified electrospun nanofibrous substrate

摘要

Graphical abstractA novel high flux electrospun nanofibrous membranes (ENMs) supported NF membranes were fabricated by phase inversion on LBL assembly modified ENMs. The obtained membranes exhibited comparable salt rejections but a much higher flux compared with conventional NF membranes prepared by phase inversion only.Display OmittedHighlights•Novel high flux NF membranes supported by ENMs were fabricated.•Fabrication process included electrospinning, LBL assembly, and phase inversion.•Introduction of ENMs significantly enhanced the membrane permeations.AbstractHerein, high flux nanofiltration (NF) membranes were fabricated by combined procedures of electrospinning, layer-by-layer (LBL) assembly, and phase inversion. The membranes displayed three-dual structure constituted polyether sulfone (PES) coating layer, LBL assembly modified electrospun polyester (PET) nanofibrous mats, and non-woven supports. High flux NF membranes thus prepared are characterized by ultrathin phase inversion layer (∼10μm) while that of conventional membranes are 100–150μm, implying that very high flux could be expected. Various factors including electrospinning conditions, chitosan (CHI)/alginate (ALG) concentration, PES concentration, exposed time, coagulating temperature, thermal treatment, and sulfonated poly ether ketone (SPEEK) content were systematically investigated. Structures of the membranes were characterized by field emission scanning electron microscopy (FESEM), mechanical properties test, Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) and static contact angle measurements. The separation experiments indicated that thus prepared membranes exhibited high flux of as high as ∼75Lm−2h−1with Mg SO4rejection of ∼80%.