Synthesis and performance of a novel nanofiltration membrane with a crosslinked sulfonated polysulfone separation layer

The composite nanofiltration membrane was prepared by coating the covalent crosslinked sulfonated polysulfone on porous substrate. Polyethylene glycol (PEG), dopamine(DA) and m-phenylenediamine (MPD) were used as crosslinkers, respectively. The polyethersulfone/sulfonated polysulfone substrate was prepared by phase inversion. The membrane surface chemistry, hydrophilicity, morphology, PWF and rejections of PEG, methyl red and Na2SO4 were characterized. The effects of different crosslinkers and their concentrations on membrane characteristics were investigated. The effect of the sulfonated polysulfone concentration on the membrane characteristic was also investigated. The PEG crosslinked membrane showed the lowest contact angle of 9.0 degrees, the highest PEG-600 rejection of 99.8%, the highest methyl red rejection of 99.8%, and the rejection of Na2SO4 was 93.4% and the PWF was 3.1Lm(-2)h(-1). The DA crosslinked membrane had the highest PWF of 51.5Lm(-2)h(-1), and the rejections of PEG-600, methyl red and Na2SO4 were 46.0, 44.0, and 34.0%, respectively. The MPD crosslinked membrane had the lowest PWF and rejections.