Preparation And Properties Of GO/quaternized Modified PSF Composite Ultrafiltration Membrane

Ultrafiltration is between the range of nanofiltration and microfiltration,which is a sieve pole separation process using pressure as the driving force.And the ultrafiltration membrane has widely applied in the field of material recovery,solution concentration and water treatment et al.However,poor hydrophicity,membrane fouling and low separation efficiency are core reason that limited the application of ultrafiltration membrane.The main research target of the paper is to prepare the organic-inorganic composite membrane via introducing the grapheme oxide(GO)into polysulfone(PSF)ultrafiltration membrane,and using chemical process to improve the dispersity of GO in PSF casting solution.Therefore,the structure of membrane channel,separation efficiency and hydrophicity could be improved.In our research,the optimal process conditions of membrane preparation was determined firstly and a PSF ultrafiltration membrane was prepared according to investigate the various single factors on the effects of structure and performance of PSF ultrafiltration membrane in process,and the factors include concentration of PSF,temperature and evaporation time of casting solution and temperature of coagulation bath.Then,GO was introduced into PSF casting solution,and using the specific physicochemical property of GO to improve membrane performance.The PSF was quaternized,and GO was immobilized in the PSF casting solution via the electrostatic interactions between GO and the quaternary ammonium groups,so that the dispersity and compatibility of GO in PSF casting solution were improved.Finally,a novel quaternized PSF/GO composite membrane(Q-PSF/GO)was prepared.The membrane structure and performance among PSF ultrafiltration membrane,PSF/GO blend ultrafiltration membrane and Q-PSF/GO composite membrane were investigated.The results shows that Q-PSF/GO composite membrane exhibited highest permeability and rejection rate to BSA compared to bare PSF membrane and PSF/GO membrane.Expressly,when the same amounts of GO was incorporated into the PSF/GO membrane and the Q-PSF/GO composite membrane,the Q-PSF/GO composite membrane showed a more satisfactory performance than the former.The water contact angle measurement confirmed the increased hydrophilicity of the Q-PSF/GO composite membrane.It was proved by the images of the FE-SEM that theQ-PSF/GO0.5 composite membrane possesses a larger and more vertical finger-like pore structure in comparison with unfilled PSF membrane and PSF/GO membrane.And the Q-PSF/GO0.5 composite membrane could adsorb a thick and incompact absorbed layer of BSA onto the surface proved by CLSM observation.However.the absorbed layer of BSA on Q-PSF/GO0.5 composite membrane surface was wash away easier than that of the PSF membrane.