Nanofiltration (NF) is widely used in separation of ions with different sizes and charges. However, thin-film composite NF membrane is hard to reach satisfied selectivity for monovalent/divalent salts separation. Herein, a novel host-guest NF membrane was designed and fabricated with cucurbituril-polyethyleneimine (CB-PEI) complex, which provided a “ring-like” supramolecular channel. The results indicated that CB-PEI/PSf membrane showed attractive separation performance for monovalent/divalent salts separation, purification and desalination of small molecule solutions. The as-prepared CB-PEI/PSf membrane exhibited superior pure water permeability up to 25.6 L·m⁻²·h⁻¹·bar⁻¹, and salt rejections of 97.4%, 90.6%, 41.9% and 12.4% to MgSO₄, Na₂SO₄, MgCl₂ and NaCl, respectively. The monovalent/divalent selectivelies for NaCl/MgSO₄ and NaCl/Na₂SO₄ reached up to 30.0 and 8.9, respectively. Besides, the CB-PEI/PSf membrane exhibited very high separation factors for medicine/NaCl and dye/NaCl mixtures. Moreover, NF membrane processes were designed and operated for monovalent/divalent mixed salt separation by using CB-PEI/PSf membrane. The NaCl with mass fraction above 98% was successfully recovered after the single-stage membrane separation of NaCl/MgSO₄ mixture and the two-stage membrane separation of NaCl/Na₂SO₄ mixture. Therefore, this novel host-guest NF membranes and process design provide a valuable basis for the industrial application of monovalent/divalent salts separation.

纳滤 (NF) 广泛用于分离具有不同大小和电荷的离子。然而，薄膜复合纳滤膜很难达到满意的单价/二价盐分离选择性。在此，使用葫芦脲-聚乙烯亚胺 (CB-PEI) 复合物设计和制造了一种新型的主客体 NF 膜，该复合物提供了一个“环状”超分子通道。结果表明，CB-PEI/PSf膜在小分子溶液的一价/二价盐分离、纯化和脱盐方面表现出良好的分离性能。所制备的CB-PEI/PSf膜表现出优异的纯水渗透性，高达25.6 L·m ^-2 ·h ^-1 ·bar ^{-1 ，对MgSO} ₄的脱盐率分别为97.4%、90.6%、41.9%和12.4%、Na ₂ SO ₄、MgCl ₂和NaCl。_{NaCl/MgSO 4}和NaCl/Na ₂ SO ₄的单价/二价选择性分别达到30.0和8.9。此外，CB-PEI/PSf 膜对药物/NaCl 和染料/NaCl 混合物表现出非常高的分离因子。此外，NF 膜工艺被设计和操作用于使用 CB-PEI/PSf 膜分离一价/二价混合盐。NaCl/MgSO ₄混合物的单级膜分离和NaCl/Na ₂ SO _{4的两级膜分离成功回收了质量分数在98%以上的NaCl}混合物。因此，这种新颖的主客体纳滤膜和工艺设计为单价/二价盐分离的工业应用提供了宝贵的基础。