Tuning the reactivity and diffusion of amine monomers in interfacial polymerization (IP) process could efficiently regulate the formation and structure of the polyamide (PA) selective layer. Herein, novel thin-film composite NF membranes with dense and ultrathin PA selective layer were fabricated using 1,3,5-benzenetricarbonyl trichloride (TMC) and ultra-low concentration triaminoguanidine (Tg) as reactive monomers. Fabrication parameters, including Tg concentration, NaOH concentration and reaction time, were systematically explored to optimize the desalination performance of PA-Tg NF membrane. During the stability test over 48 h, PA-Tg-0.06 membrane displayed a water permeance of ∼12 L m⁻² h⁻¹·bar⁻¹ and Na₂SO₄ rejection of ∼99%. Meanwhile, detailed comparisons were made between PA-Tg NF membrane and a typical NF membrane fabricated with PIP as an aqueous monomer, including characteristics of the monomers as well as the structure, water permeance, salt rejection and antifouling property of the membranes. Molecular dynamics simulation and interfacial diffusion experiments indicated that the Tg monomer exhibited a higher reactivity but a lower diffusivity than the PIP monomer, making it feasible for the fabrication of PA-Tg NF membrane with ultra-low concentration of Tg monomer. In addition, compared with the PA-PIP membrane, the PA-Tg membrane exhibited a smoother, more hydrophilic and negatively charged surface, as well as a thinner and denser selective layer, thereby showing a higher water permeance, salt rejection and stronger fouling resistance.

在界面聚合 (IP) 过程中调整胺单体的反应性和扩散可以有效地调节聚酰胺 (PA) 选择层的形成和结构。在此，使用 1,3,5-苯三羰基三氯化物 (TMC) 和超低浓度三氨基胍 (Tg) 作为反应单体，制备了具有致密和超薄 PA 选择层的新型薄膜复合纳滤膜。系统地研究了包括 Tg 浓度、NaOH 浓度和反应时间在内的制造参数，以优化 PA-Tg NF 膜的脱盐性能。在超过 48 小时的稳定性测试中，PA-Tg-0.06 膜表现出 ∼12 L m ⁻²  h ⁻¹ ·bar ⁻¹和 Na ₂ SO _{4的透水性}约 99% 的拒绝率。同时，对PA-Tg纳滤膜与以PIP为水性单体制备的典型纳滤膜进行了详细比较，包括单体的特性以及膜的结构、透水性、脱盐率和防污性能。分子动力学模拟和界面扩散实验表明，与PIP单体相比，Tg单体具有更高的反应活性，但扩散系数更低，这使得制备超低Tg单体浓度的PA-Tg NF膜成为可能。此外，与PA-PIP膜相比，PA-Tg膜具有更光滑、更亲水和带负电的表面，以及更薄更致密的选择性层，从而表现出更高的透水率、脱盐率和更强的抗污染能力.