Study On Hydrophilic Modification And Performance Of Polysulfone Ultrafiltration Membrane

Polysulfone material has excellent mechanical properties and membrane processing properties,but it has strong hydrophobicity and poor stain resistance.In this study,the polysulfone ultrafiltration membrane was prepared by the immersion precipitation phase inversion method.The surface of the polysulfone ultrafiltration membrane was hydrophilically modified by dopamine and taurine to prepare an anti-fouling polysulfone composite ultrafiltration membrane.The composition of the composite membrane was characterized by Fourier transform infrared spectroscopy(FTIR).The morphology of the composite membrane was studied by scanning electron microscope(SEM).The comprehensive performance of the membrane was investigated by ultrafiltration test,contact angle test,mechanical performance test and anti-pollution test.(1)Polysulfone(PSF)was used as the base membrane material.The effects of polysulfone content and additive polyvinylpyrrolidone(PVP)content on membrane structure and performance were investigated.When the content of PSF was 16 wt% and the content of PVP was 8 wt%,the overall performance of the prepared polysulfone ultrafiltration membrane was the best.(2)The surface modification and blending modification of the polysulfone basement membrane were carried out with dopamine(DA).The results showed that polydopamine(PDA)was successfully introduced into the polysulfone membrane.The performance of the modified PSF/PDA composite membrane was obviously better than that of the polysulfone substrate membrane.In contrast,the performance of the modified PSF/PDA composite membrane was better.In the process of surface modification with dopamine,the two factors affecting the structure and performance of the membrane,the coating time of dopamine and the concentration of dopamine,were investigated.The best modification conditions were that the dopamine coating time was 18 h and the dopamine concentration was 1.5 g/L.(3)The effects of taurine(TA)concentration and taurine reaction time on the structure and performance of the membrane were investigated.When the taurine concentration was2 g/L and the taurine modification time was 8 h,the water flux of the PSF/PDA-TA composite membrane increased by nearly 62%.The overall performance of the membrane was obviously improved.The anti-pollution performance test results showed that the flux recovery rate of the PSF/PDA-TA composite membrane increased,the irreversible pollution coefficient and the total pollution coefficient decreased,and the reversible pollution coefficient increased.It was confirmed that the anti-fouling performance of the PSF/PDA-TA composite membrane was improved.