The strategy of introducing a hydrophilic interlayer on the porous substrate has been widely applied in the modification of nanofiltration (NF) membranes. Herein, an environmentally friendly polycarboxylic interlayer is prepared from the mixture of catechol and sodium periodate (SP). Catechol is easy to oxidize to generate reactive o-quinones which undergoes phenolic polymerization to form covalent polymer with the carboxyl group, with the effect of SP initiation. Due to the introduction of carboxylic group, the interlayer is hydrophilic and can store more piperazine molecules to provide a more uniform platform for interfacial polymerization, which is conductive to form a thin and dense polyamide (PA) active layer. Compared with the traditional membrane, the modified thin film composite (TFC) membrane exhibits 1.7-fold of permeance (up to 15.4 ± 1 L·m⁻²·h⁻¹ bar⁻¹), maintaining a high rejection of Na₂SO₄ (98.42 ± 1.2%). Although the TFC membrane without an interlayer tends to be thick and defective in low PIP concentration, the role of the interlayer can eliminate this limitation. Besides, the modified TFC membrane possesses a high electronegativity with the fact that isoelectric point (3.29) has been lower than that of the traditional membrane, which has the potential to separate negative organic pollutants in the wastewater treatment.

在多孔基材上引入亲水性中间层的策略已被广泛应用于纳滤（NF）膜的改性。在此，由邻苯二酚和高碘酸钠（SP）的混合物制备环境友好的聚羧酸中间层。邻苯二酚很容易被氧化生成反应性邻苯二酚，在SP引发的作用下，邻苯二酚会发生酚类聚合反应，形成具有羧基的共价聚合物。由于引入了羧基，该中间层是亲水性的，可以存储更多的哌嗪分子，从而为界面聚合提供更均匀的平台，该平台导电以形成薄而致密的聚酰胺（PA）活性层。与传统膜相比，改性薄膜复合（TFC）膜的渗透率为1.7倍（高达15倍）。^-2 ·h ^-1  bar ^-1），保持了高的Na ₂ SO ₄截留率（98.42±1.2％）。尽管没有夹层的TFC膜倾向于变厚并且在低的PIP浓度中存在缺陷，但是夹层的作用可以消除该限制。此外，改性的TFC膜具有较高的电负性，其等电点（3.29）低于传统膜的等电点，在废水处理中具有分离负有机污染物的潜力。