磁性诱导强制两性离子/POSS球表面偏析制备高通量、抗污染纳滤膜

Preparation of high-flux and anti-fouling nanofiltration membranes through forced zwitterionic/POSS nanoparticles surface segregation in magnetic field

低渗透通量和膜污染是制约纳滤膜发展的瓶颈.针对纳滤膜材料渗透性与选择性相互制约及分离过程中的膜污染等问题,在非溶剂诱导相转化制膜过程中,强制两性离子/POSS改性的磁性纳米颗粒在膜表面偏析,调节高分链间距、自由体积/通道尺寸等物理化学微环境,提高纳滤膜通量;在膜表面偏析的两性离子官能团可以提高纳滤膜抗污染性能.通过优化工艺条件,制备的纳滤膜水通量高达500 L/(m^(2)·h·Mpa),同时对甲基蓝、刚果红的截留率均在95%以上.

Low permeability and membrane fouling are the bottlenecks restricting the development of nanofiltration membranes.To address the issues of trade-off between permeability and selectivity of membrane,as well as membrane fouling,the membranes were prepared through forced zwitterionic/POSS nanoparticles surface segregation in magnetic field during non-solvent-induced phase inversion process.The process can adjust the physicochemical microenvironment such as polymer chain spacing and free volume/channel size,thereby enhancing the flux of the nanofiltration membrane.The zwitterionic functional groups segregated on the membrane surface can improve the antifouling performance of the nanofiltration membrane.The optimized nanofiltration membrane achieved a high water flux of up to 500 L/(m^(2)·h·MPa),while the retention for both methyl blue and Congo red were remained above 95%.