In this study, a new kind of aromatic diamine monomer named as 1,4-bis(4-aminophenyl)piperazine (BANPZ) was particularly designed and synthesized, and then the novel zwitterionic polyimide (ZPI) was prepared through a two-step process including polycondensation and quaternary amination reaction. The chemical structures of the prepared monomer and polymers were identified by FTIR and ¹H NMR measurements, respectively. Meanwhile, the inherent viscosities, molecular weights, solubility behaviors and thermal properties of two obtained polymers were thoroughly characterized. Compared with the control polyimide (PI) membrane, the presence of zwitterionic groups considerably improve the hydrophilicity of the ZPI membrane, thereby enhancing the water permeability to some extent without obviously affecting the rejection ratio. Based on the static protein adsorption and dynamic cycle ultrafiltration experiments, the ZPI membrane exhibited persistent antifouling property, which was demonstrated by the flux decline ratio and filtration resistance. In particular, the water flux recovery ratio of the ZPI membrane was retained at 96.0% after a three-cycles of BSA solution filtration, which was much higher than that of the PI membrane (76.7%), suggesting excellent long-term performance stability. This new approach provided a valuable strategy of combining polymer chemical structure optimization and mature non-solvent induced phase separation (NIPS) method, which could greatly drive the development and application range of separation membranes.

本研究特别设计合成了一种新型的芳香族二胺单体1,4-双（4-氨基苯基）哌嗪（BANPZ），然后通过两步法制备了新型两性离子聚酰亚胺（ZPI）。包括缩聚和季胺化反应。FTIR和¹鉴定了制备的单体和聚合物的化学结构。1 H NMR测量分别。同时，对得到的两种聚合物的固有粘度，分子量，溶解行为和热性能进行了彻底表征。与对照聚酰亚胺（PI）膜相比，两性离子基团的存在可显着提高ZPI膜的亲水性，从而在不明显影响截留率的情况下在一定程度上提高水的渗透性。通过静态蛋白质吸附和动态循环超滤实验，ZPI膜表现出持久的防污性能，这由通量下降率和过滤阻力证明。特别是，经过三轮BSA溶液过滤后，ZPI膜的水通量回收率保持在96.0％，远高于PI膜的水通量回收率（76.7％），表明长期的性能稳定。这一新方法提供了将聚合物化学结构优化与成熟的非溶剂诱导相分离（NIPS）方法相结合的有价值的策略，这将极大地推动分离膜的开发和应用范围。