To break the “trade-off” effect and alleviate fouling of nanofiltration (NF) membranes, a variety of polyhedral oligomeric silsesquioxane (POSS) nanomaterials with different functional groups were selected to modify the selective layer. The feasibility of POSS-modified membranes and their performance have been comprehensively evaluated. Compared to the hydrophobic POSS, the water-soluble POSS endowed the NF membranes with enhanced permeability and selectivity owing to the hydrophilic groups and the excellent diffusion in the aqueous solution. Furthermore, the octylamino-POSS was effectively activated by triethylamine, generating more amino groups and participating in the IP process, and providing effective routes to sieve water and Na₂SO₄. The resultant membrane, i.e., OPN(II) membrane, presented significantly better performance than the pristine PA membrane, both in water flux (90 L/m²h vs. 58 L/m²h) and rejection of Na₂SO₄ (98% vs. 91%). This OPN(II) membrane also showed consistently higher rejections for all tested salts and recalcitrant organics, accompanying with the improved stability and antifouling capability. Its flux recovery ratio reached up to 85.0%, higher than that of the PA membrane of 79.2%. This work has provided a facile method to prepare thin film composite membrane with enhanced performance, thereby outlining a new way to break the “trade-off” effect of NF membranes.

为了打破“权衡”效应并减轻纳滤（NF）膜的污染，选择了多种具有不同官能团的多面体低聚倍半硅氧烷（POSS）纳米材料来修饰选择性层。对POSS改性膜的可行性及其性能进行了全面评估。与疏水性POSS相比，水溶性POSS由于亲水基团和在水溶液中的优异扩散性而赋予NF膜更高的渗透性和选择性。此外，辛氨基-POSS被三乙胺有效活化，产生更多氨基并参与IP过程，为筛分水和Na ₂ SO _{4提供了有效途径}. 所得膜，即 OPN(II) 膜，在水通量（90 L/m ² h 与 58 L/m ² h）和 Na ₂ SO ₄截留率（ 98% 与 91%）。这种 OPN(II) 膜对所有测试的盐和顽固的有机物也始终显示出更高的排斥率，同时具有更高的稳定性和防污能力。其通量恢复率高达85.0%，高于PA膜的79.2%。这项工作为制备具有增强性能的薄膜复合膜提供了一种简便的方法，从而为打破纳滤膜的“权衡”效应开辟了一条新途径。