Low-pressure nanofiltration (NF) has evinced huge application prospects for ion/molecule separation. However, current polyamide-based membranes made by highly reactive monomers offer less control in precisely tuning of their pore apertures, leading to a permeability-selectivity trade-off limit. Herein, the usage of amino-piperidine (AP, 4-aminopiperidine: 4AP; 3-aminoapiperidine: 3AP) is proposed as new building block that interfacially polymerizes with trimesoyl chlorides (TMC) onto a nanofibrous hydrogel to fabricate high-performance thin film composite (TFC) membranes. The resultant amino-piperidine thin film composite (AP-TFC) membranes with nodular and bubble-like surface have high hydrophilicity, electronegativity, and moderate crosslinking degree. Introducing an alkane bond length based on the piperidine structure allows to finely augment the free-volume elements of polyamide-based membranes, combined with varying the monomer concentrations. Furthermore, the 4AP-TFC membranes showed an excellent water permeability of 35.0 L m⁻² h⁻¹ bar⁻¹ with Na₂SO₄ rejection above 98.5% when the 4AP concentration was 0.05 w/v%. The 4AP-TFC membrane was also found having a superior sieving capability for antibiotics, attributed to the synergy of size exclusion by well-defined ultra-microporous structure (<0.7 nm) and electrostatic repulsion due to the abundance of surface negative charges. This work provides the guideline of using AP molecules for the fabrication of high-crosslinked TFC membranes with potential applications in low-pressure NF, organic solvent NF, and related water purification.

低压纳滤（NF）在离子/分子分离方面具有巨大的应用前景。然而，目前由高反应性单体制成的基于聚酰胺的膜在精确调节其孔孔径方面提供的控制较少，导致渗透选择性权衡限制。在此，提出了使用氨基哌啶（AP，4-氨基哌啶：4AP；3-氨基哌啶：3AP）作为与均苯三甲酰氯（TMC）在纳米纤维水凝胶上进行界面聚合以制备高性能薄膜复合材料的新型构件。 (TFC) 膜。所得的氨基哌啶薄膜复合(AP-TFC)膜具有结节状和气泡状表面，具有较高的亲水性、电负性和适中的交联度。引入基于哌啶结构的烷烃键长可以精细地增加基于聚酰胺的膜的自由体积元素，并结合改变单体浓度。此外，4AP-TFC 膜具有 35.0 L m 的优异透水性^-2  h ^-1  bar ^-1 ，当 4AP 浓度为 0.05 w/v% 时，Na ₂ SO ₄排斥率高于 98.5%。还发现 4AP-TFC 膜对抗生素具有出色的筛分能力，这归因于明确定义的超微孔结构 (<0.7 nm) 的尺寸排阻和由于表面负电荷丰富而产生的静电排斥的协同作用。这项工作为使用 AP 分子制备高交联 TFC 膜提供了指导，该膜在低压纳滤、有机溶剂纳滤和相关水净化中具有潜在应用。