传统纳滤膜主要通过界面聚合法制备，其分离层与基膜之间的而结合力为分子间作用力较为薄弱。本工作通过在分离层与基膜之间引入配位键，采用金属-有机配位技术在聚酰亚胺基膜上制备了具有纳滤性能的分离层。首先通过考察氢氧化钠溶液的浓度和反应时间对于基膜形貌和基团的影响，优化基膜的修饰程度，确定最佳的氢氧化钠溶液浓度为0.01 mol/L，修饰时间为9 min。然后通过Fe3+与Na+之间的置换将配位中心Fe3+引入基膜表面。最后考察不同金属配位中心与有机配体之间的比例对膜性能的影响，确定最优植酸与铁离子的摩尔比例为3:7。制得的配位纳滤膜表面负电性与亲水性都得到增强。制得的膜对Na2SO4截留率为85.6%，通量为5.3 L m-2h-1bar-1，对多种染料的截留率在99%以上，且具有较好的长期稳定性。

Traditional thin-film composite nanofiltration membranes fabricated by interfacial polymerization possess intermolecular force as the interaction between the active layer and substrate. This may lead to the peel-off of the active layer during the working process. In this work, based on the introduction of the coordination bond between the active layer and substrate, the active layer with nanofiltration performance was fabricated on a polyimide substrate by metal-organic coordination technology. Firstly, the modification degree of the substrate was optimized by investigating the effect of the NaOH concentration and the reaction time on the morphology and functional groups of the substrate surface. The optimum concentration and reaction time are 0.01 mol/L and 9 min respectively. Then, the coordination center Fe3+ was introduced to the substrate by replacing the Na+ on the modified substrate with Fe3+. Finally, the effect that the ratio of metal coordination centers and organic ligands has on the membrane performance were studied, and the optimized mole ratio of PA and Fe3+ is 3:7. The hydrophilicity and negative charge of the obtained membrane are both enhanced. The rejection and permeability of the coordination nanofiltration membrane towards 1000 ppm Na2SO4 solution is 85.6% and 5.3 L m-2h-1bar-1 respectively. Additionally, the membranes have a high rejection towards a variety of dyes and excellent long-term stability.

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