Preparation And Performance Of Polysulfone Membrane Modified By Sulfonated Polytrifluorostyrene

Polysulfone(PSF)as a common material of substrate membrane,not only has excellent chemical inertness,thermal stability and mechanical properties,but also has great film-forming ability,so it plays an important role in the field of water treatment,gas separation,hemodialysis,cell culture,and artificial liver.However,PSF membrane are easily polluted due to its hydrophobicity,which can reduce membrane flux and life span,and increase maintenance costs.Therefore,to strengthen hydrophilicity and anti-pollution,and expand applications of PSF membranes,this paper investigates the structure and applications of modified PSF membranes and the performance of layer-by-layer self-assembled PSF nanofiltration(NF)membranes and applications in dye separation.In this paper,we blend the additive to prepare PSF/SPTFS membranes through phase seperration,and investigate the structures and performance.Based on the PSF ultrafiltration(UF)and NF membranes at home and abroad,PSF/SPTFS membranes were prepared by a nonsolvent induce phase separation method using polysulfone as the base material,polyvinylpyrrolidone(PVP)as the pore-forming agent and sulfonated polytrifluorostyrene(SPTFS)as an additive.And investigated the effects of SPTFS addition on structure,hydrophilicity,surface and anti-pollution performance.Compared with PSF membranes(M0),the water flux of PSF/SPTFS membranes doubled.With the increase of SPTFS addition,the surface layer was thickened and the structure from finger-like change to macrovoids and finally to sponge-like structure.Meanwhile,contact angle,surface zeta potential,and static protein adsorption of PSF/SPTFS membranes also decreased.In summary,the PSF/SPTFS composite membrane exhibited overall high flux,hydrophilicity and highly negative surface.The PSF/SPTFS membrane M1 showed less contaminant and high pollution removal rate(30.8%)than M0 in quartz crystal microbalance(QCM)real-time monitoring.The results showed that the anti-pollution of the PSF/SPTFS membrane with SPTFS addition of0.05 wt.%was somewhat enhanced.In this paper,we prepare NF membranes through layer-by-layer self-assembly and study the structure and separation properties.PSF/SPTFS membrane with 0.10 wt.%SPTFS addition was selected as substrate,and polyethyleneimine(PEI)and SPTFS as the polycation and polyanion respectively to fabricate the NF membranes with different PEI/SPTFS bilayers.The effects of PEI/SPTFS bilayers on the morphology,surface properties and dye/salt separation performance of NF membranes were investigated.The results showed that both the hydrophilicity and permeability showed a decreasing trend with the increasing of PEI/SPTFS bilayers,membrane deposited with single PEI/SPTFS bilayer(SM-1)and two PEI/SPTFS bilayers(SM-2)exhibited high water flux of28.0(L/m~2h bar)and 15.6(L/m~2h bar)respectively.Meanwhile,SM-1 and SM-2 showed high dye separation abilities,SM-2 with a dense surface and smaller pore size which can reject dye of more than 99%,SM-1 has a rejection of 98%for methyl blue(MB),Congo red(CR)and acid red 66(AR66),and 95%for methyl orange(MO).In addition,the low surface energy of the SPTFS layer on NF membrane gave it ultralow static protein adsorption.