Composite nanofiltration (NF) membranes with anti-bacterial activity were prepared by electrostatic self-assembly. A novel composite (Ag⁺-PEI/ Cu²⁺-PEI/ Fe³⁺-PEI) was obtained by the chelate reaction of polyethylenimine (PEI) with metal ion, which constituted the main component of the separation layer of the prepared membrane. Three composite (Ag⁺-PEI/ Cu²⁺-PEI/ Fe³⁺-PEI) NF membranes prepared at optimized condition exhibited excellent permeability (121 L·m⁻²·h⁻¹·MPa⁻¹/71 L·m⁻²·h⁻¹·MPa⁻¹/ 73 L·m⁻²·h⁻¹·MPa⁻¹) and high rejection (96.5%/ 94.5%/ 91.6%) for acid fuchsin as well as low rejection (31.5%/ 27.5%/ 23.7%) for MgSO₄. Meanwhile, the higher flux recovery ratio (FRR) of dye was observed for the Fe³⁺-PEI membrane (FRR_Fe=91.5%) than that for others ((FRR_Cu=83.2%) and (FRR_Ag=76.4%)). Furthermore, these three NF membranes also presented good hydrophilicity (59°/39°/35°), excellent anti-bacterial activity (up to 95% against E. coil and over 90% against S. aureus) and good long-term stability in our trails. These results were of great significance for dye recycle in industrial field.

通过静电自组装制备具有抗菌活性的复合纳滤膜。通过聚乙烯亚胺（PEI）与金属离子的螯合反应，得到了一种新型的复合物（Ag ⁺ -PEI / Cu ²⁺ -PEI / Fe ³⁺ -PEI），它是所制备膜的分离层的主要成分。三复合（AG ⁺ -PEI /铜²⁺ -PEI /铁³⁺ -PEI）NF膜在优化条件下制备表现出优异的透气性（121 L·米^-2 ·H ^-1 ·MPa以下^-1 / 71 L·米^{- 2} ·h ^-1 ·兆帕^-1 / 73 L·m ^-2 ·h^-1 ·MPa ^-1）和酸性品红的高排阻率（96.5％/ 94.5％/ 91.6％）以及MgSO _4的低排阻率（31.5％/ 27.5％/ 23.7％）。同时，观察到Fe ³⁺ -PEI膜（FRR _Fe = 91.5％）比其他膜（（FRR _Cu = 83.2％）和（FRR _Ag = 76.4％）更高的染料通量恢复率（FRR）。。此外，这三种NF膜还表现出良好的亲水性（59°/ 39°/ 35°），出色的抗菌活性（对大肠埃希菌的抵抗力高达95％，对金黄色葡萄球菌的抵抗力超过90％），并在我们的跟踪中保持良好的长期稳定性。这些结果对工业领域的染料回收具有重要意义。