Zwitterionic materials containing equal proportions of positively and negatively charged groups have been used to provide membranes with antifouling capabilities. This study focuses on the modification of a commercially available polyamide thin-film composite membrane with a zwitterionic material and investigates its effectiveness in fouling mitigation. The zwitterionic material, sulfobetaine vinylimidazole (SBVI), was synthesized by reacting 1,3-propane sulfone with 1-vinyl imidazole. A NF90 polyamide membrane functionalized with propagyl bromide was modified by the polymerization of SBVI on its surface. Various techniques were used to verify the successful modification of membranes. The water flux and salt rejection of the pristine and modified membranes were measured under comparable stabilization conditions, and showed an increase in salt rejection and a decrease in permeability for the modified membrane because of additional membrane resistance. However, fouling tests conducted with a wide range of foulants in cross-flow filtration mode showed a lower fouling ratio and higher recovery ratio for the modified membrane than for the pristine membrane. The enhancement in the antifouling characteristics of the modified membrane was mainly attributed to the improvement in hydrophilicity resulting from the zwitterionic brushes. Our results demonstrated the fouling resistance is further reinforced in an ionic environment through the “salting-in” effect.

含有等比例的带正电和带负电的基团的两性离子材料已被用来为膜提供防污能力。本研究的重点是用两性离子材料对市售聚酰胺薄膜复合膜进行改性，并研究其在缓解污垢方面的有效性。两性离子材料磺基甜菜碱乙烯基咪唑(SBVI)是通过1,3-丙烷砜与1-乙烯基咪唑反应合成的。通过在其表面聚合 SBVI 对溴丙烷功能化的 NF90 聚酰胺膜进行改性。使用各种技术来验证膜的成功修饰。在相当的稳定条件下测量了原始膜和改性膜的水通量和脱盐率，结果表明，由于额外的膜阻力，改性膜的脱盐率增加，而渗透性下降。然而，在错流过滤模式下对多种污染物进行的结垢测试表明，与原始膜相比，改性膜具有较低的结垢率和较高的回收率。改性膜防污特性的增强主要归因于两性离子刷亲水性的改善。我们的结果表明，在离子环境中，通过“盐溶”效应，抗污性得到进一步增强。