雙離子系統改質已被廣泛研究在膜表面以提升防汙性能,但主要以表面改質為主,使得膜至被過程中冗長難以擴大規模及商業化,所以在薄膜改質過程中能夠有效地導入雙離子系統改質為最理想的狀態,但雙離子材料與基材經常出現相容性的問題,所以在此加入(甲基丙烯酸甲酯-聚乙二醇甲基丙烯酸乙二醇酯-磺基甜菜鹼甲基丙烯酸甲酯)(PMMA-co-PEGMA-co-PSBMA)的共聚物形成雙離子聚偏二氟乙烯膜。其中甲基丙烯酸甲酯鏈段為提供與聚偏二氟乙烯的疏水作用力,聚乙二醇甲基丙烯酸乙二醇酯與磺基甜菜鹼甲基丙烯酸甲酯做為溶解度和抗汙基團。利用蒸氣式相轉換誘導分離成膜後,對其做膜結構分析(SEM, AFM, FT-IR, WCA等),利用甲基丙烯酸甲酯-聚乙二醇甲基丙烯酸乙二醇酯-磺基甜菜鹼甲基丙烯酸甲酯共聚高分子來提升膜抗沾黏性質之效果,減少生物汙垢(大腸桿菌、纖維蛋白、牛血清蛋白、解將蛋白及血球細胞),此應證了薄膜改質可發生於整片膜塊,由於雙離子之雙連續薄膜成形的膜過濾系統應用範圍很廣泛,可用於廢水處理到生物醫學相關應用。
Zwitterionic modifications have been widely investigated to endow surfaces of membranes with fouling resistance. However, the approaches reported are mostly surface modifications, making the membrane preparation lengthy and difficult to scale-up. Ideally, zwitterionization should be achieved during membrane formation, but compatibility issues frequently arise between the zwitterionic material, hydrophilic, and the matrix polymer, hydrophobic. Here, a poly(methyl methacrylate-co-ethylene glycol methacrylate-co-sulfobetaine methacrylate) (PMMA-co-PEGMA-co-PSBMA) copolymer is introduced to form zwitterionic poly(vinylidene fluoride) (PVDF) membranes. The MMA segments are used to form hydrophobic interactions with PVDF, while PEGMA units and SBMA units are employed as solubility-enhancing groups and antifouling groups, respectively. After forming the membranes by the vapor-induced phase separation, followed by their complete characterization (SEM, AFM, FT-IR, mapping FT-IR, WCA, etc.), it is shown that PMMA-co-PEGMA-co-PSBMA reduces membrane biofouling by a large span of biofoulants (Escherichia coli, fibrinogen, BSA, proteins from plasma, blood cells), which validates the design of the copolymer and the in-situ modification. The range of application of these zwitterionic bi-continuous microfiltration membranes is wide, going from wastewater-treatment to biomedical-related applications.