Presently, advanced Thin-film nanocomposite (TFN) nanofiltration membranes fabricated using microporous materials displayed distinctly enhanced separation performance. Herein, tetrakis(hydroxymethyl) phosphonium chloride (THPC)-modified COF nanosheets (termed as IL@COF-367 NSs) were designed as the intermediate layer to construct a high-hydrophilic membrane support, with the purpose of regulating interfacial polymerization (IP) to optimize the physicochemical characters of polyamide films. Due to the high hydrophilicity and favored dispersion of IL@COF-367 NSs in aqueous phase, the as-fabricated COF nanosheet interlayer not only promotes uniform distribution of amine monomers, but also slows down their diffusion toward the organic interface. Compared pristine thin-film composite (TFC) membranes, the IC-TFN membranes yield a nodular polyamide film with a higher surface roughness (from 14.5 to 54.5 nm) and a lower film thickness (from 95 to 30 nm). Introducing IL@COF-367 NSs additionally improves the pore size (from 0.31 to 0.47 nm) of the functionalized TFN membrane revealed by the MWCO measurement. Consequently, IL@COF-367 NSs-interlayer polyamide (IC-TFN) membrane manifests a high permeability of 36.5 L m⁻² h⁻¹ bar⁻¹ and satisfactory Na₂SO₄ rejection of 98.5 %. The usage of 2D hydrophilic COF nanosheet as an interlayer to optimize the polyamide membranes offers a guideline for the design of high-performance TFN membrane.

目前，使用微孔材料制造的先进薄膜纳米复合材料 (TFN) 纳滤膜显示出明显增强的分离性能。在此，四（羟甲基）氯化磷（THPC）修饰的COF纳米片（称为IL@COF-367 NSs）被设计为中间层以构建高亲水性膜载体，目的是调节界面聚合（IP）优化聚酰胺薄膜的物理化学特性。由于 IL@COF-367 NSs 在水相中的高亲水性和有利于分散，制造的 COF 纳米片夹层不仅促进了胺单体的均匀分布，而且减缓了它们向有机界面的扩散。与原始薄膜复合 (TFC) 膜相比，IC-TFN 膜产生的结节状聚酰胺膜具有更高的表面粗糙度（从 14.5 到 54.5 nm）和更薄的膜厚度（从 95 到 30 nm）。引入 IL@COF-367 NSs 还可以改善 MWCO 测量显示的功能化 TFN 膜的孔径（从 0.31 到 0.47 nm）。因此，IL@COF-367 NSs-层间聚酰胺（IC-TFN）膜表现出 36.5 L·m 的高渗透性^-2  h ^-1  bar ^-1和98.5%的令人满意的Na ₂ SO _{4截留率。}使用二维亲水性 COF 纳米片作为中间层来优化聚酰胺膜，为高性能 TFN 膜的设计提供了指导。