Preparation And Performance Study Of Antifouling Ultrafiltration Membranes Based On Active-passive Integrated Mechanisms

Fabrication of antifouling membrane surfaces is the fundamental way to solve membrane fouling problem.In this study,with surface segregation as platform technique,the active-passive integrated mechanisms were created on ultrafiltration membrane surfaces including passive fouling-resistant,fouling-release and active antibacterial mechanisms.The integration of active and passive antifouling mechanisms could simultaneously improve the antibacterial and antifouling properties of water treatment membrane materials,wich could solve the problem that the single passive or active antifouling mechanism could not effectively resist biolouling on membrane surfaces during long-term operation.The research details were summarized as follows:Firstly,construction of active-passive integrated antifouling mechanisms including fouling-resistant,fouling-release and active conduct antibacterial mechanisms based on forced surface segregation.The amphiphilic block-like copolymer comprising low surface energy PHFBM,hydrophilic PEGMA and antibacterial PMTAC quaternary ammonium salt segments was prepared via free radical polymerization.The influence of amphiphilic modifier on membrane surface chemical composition,hydrophilicity,surface energy,antibacterial and antifouling properties was systematically investigated.The PVDF/PHFBM-PEGMA-PMTAC membrane showed superior antifouling and antibacterial properties.During oil/water emulsion filtration,the total flux decline ratio was lower than 10% and the flux recovery ration reached nearly 100%.Besides,the antibacterial activity against E.Coli was nearly 100%.Secondly,construction of active-passive integrated antifouling mechanisms including fouling-resistant,fouling-release and active release antibacterial mechanisms based on synergistic surface segregation.The amphiphilic block-like copolymer comprising low surface energy PHFBM,hydrophilic PCBMA segments was prepared via free radical polymerization.The influence of amphiphilic PHFBM-PCBMA/AgNPs composite modifier on membrane surface chemical composition,surface energy,antibacterial and antifouling properties was systematically investigated.The PVDF/PHFBM-PCBMA/Ag 5% membrane showed superior antifouling and antibacterial properties.During oil/water emulsion filtration,the total flux decline ratio was lower than 5% and the flux recovery ration reached nearly 100%.Besides,the antibacterial activity against E.Coli was nearly 100% with obvious inhibition zone.Finally,construction of active-passive integrated antifouling mechanisms including fouling-resistant,fouling-release and active contact in addition to release antibacterial mechanisms based on synergistic surface segregation.The amphiphilic block-like copolymer comprising low surface energy PHFBM,hydrophilic PMAA and antibacterial QAS PMTAC segments was prepared via free radical polymerization.The influence of amphiphilic PHFBM-PMAA-PMTAC/AgNPs composite modifier on membrane surface chemical composition,surface energy,antibacterial and antifouling properties was systematically investigated.The PVDF/PHFBM-PMAA-PMTAC/Ag 5% membrane showed superior antifouling and antibacterial properties.During oil/water emulsion filtration,the total flux decline ratio was lower than 5% and the flux recovery ration reached nearly 100%.Besides,the antibacterial activity against E.Coli was nearly 100% through contact and release antibacterial mechanisms.