Polyamide (PA) nanofiltration (NF) membranes with excellent permeability and selectivity have always been the ultimate pursuit of desalination technology. Herein, we present a guanidinium manipulated interfacial polymerization strategy to develop guanidyl-integrated PA NF membranes with ultra-high permselectivity. A nylon microfiltration membrane is utilized as the support to conduct spatial-temporal regulation of amine monomers along with controllable diffusion reaction. Through introducing 1,3-diaminoguanidine (DAG) or triaminoguanidine (TAG) into the aqueous piperazine solution, the free volumes of PA membranes could be well modulated at the sub-angstrom scale. Consequently, the TAG-integrated PA membrane exhibited high water permeance of 33.1 LMH bar⁻¹ and superior Na₂SO₄ rejection of 99.2%. Meanwhile, this membrane achieved outstanding anion sieving capability (Cl⁻/SO₄²⁻ ∼ 343) and nearly 100% tetracycline removal, which is superior to the “state-of-the-art” PA NF membranes. The DAG-integrated PA membrane attained ultra-high water permeance of 46.5 LMH bar⁻¹ due to its relatively large free volume. In addition, the nylon composite PA membranes displayed desirable anti-pressure and organic solvent-resistant abilities. This study provides a convenient and scalable preparation strategy for highly permselective NF membranes, which holds great application potential in desalination and resource recovery.

具有优异渗透性和选择性的聚酰胺（PA）纳滤（NF）膜一直是海水淡化技术的终极追求。在此，我们提出了一种胍基控制的界面聚合策略，以开发具有超高选择性渗透性的胍基集成 PA NF 膜。以尼龙微滤膜为支撑，对胺单体进行时空调控并可控扩散反应。通过将1,3-二氨基胍（DAG）或三氨基胍（TAG）引入哌嗪水溶液中，可以在亚埃尺度上很好地调节PA膜的自由体积。^{因此，集成TAG的PA膜表现出33.1 LMH bar -1}的高透水性和优异的Na₂ SO ₄截留率为99.2%。同时，该膜实现了出色的阴离子筛分能力（Cl ^- /SO ₄ ²⁻  ∼ 343）和近100%的四环素去除率，优于“最先进”的PA NF膜。由于其相对较大的自由体积，DAG集成PA膜获得了46.5 LMH bar ^{-1的超高透水性。}此外，尼龙复合PA膜还表现出良好的抗压和耐有机溶剂能力。该研究为高选择性纳滤膜提供了一种方便且可扩展的制备策略，在海水淡化和资源回收方面具有巨大的应用潜力。