| Increasing UF membrane hydrophilicity and improving its anti-fouling resistance is the focus of attention in the field. In this paper, polyethersulfone (PES)/sulfonated polysulfone (SPSf) blend ultrafiltration membrane was prepared by immersion precipitation phase inversion. The influence of compatiblity between composes and the composition and spinning technologic parameters of casting solution on the morphologies and performance of PES/SPSf blend ultrafiltration membrane were investigated.Firstly, we discussed different compatibility between the two blend systems based on Schneier theory and glass transition temperature. The study found that PES/PSf is partially compatible system, but interesting, PES/SPSf is a fully compatible system. The effects of polymer concentrations, blend ratios, molecular weights and contents of PEG on the structure and performance of PES/SPSf blend flat ultrafiltration membranes were investigated. The result showed that the PES/SPSf blend flat UF membrane with gradient sponge-like asymmetrical structure was obtained under the conditions:polymer concentration is 18wt%, PES/SPSf weight blend ratio is 84/16 and PEG (20K) content is 24wt%. The membrane hydrophilicity was significantly enhanced. The pure water flux was 1467L/m2h and BSA rejection rate was 91.4%.Finally, the influences of the bore fluid composition, coagulation bath temperature and wind speed on the microporous structures and performances were investigated under optimal casting solution composition. The result showed that with the coagulation bath temperature increased from 30℃ to 60℃, the pure water flux of PES/SPSf seven-bore hollow fiber membrane increased from 128L/m2 h to 320L/m2 h, the BSA rejection was reduced from 98% to 85%. Furthermore, as the winding speed increases, the pure water flux of the membrane is reduced, but the BSA rejection was increased.In addition, the pure water flux maximum reaches 506L/m2 h if added DMAc content of the bore fluid.
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