Current polyamide lithium extraction nanofiltration membranes are susceptible to chlorine degradation and/or low permeance, two problems that are hard to reconcile. Here we simultaneously circumvented these problems by designing a quaternized-spiro piperazine monomer and translating its beneficial properties into large-area membranes (1 × 2 m²) via interfacial polymerization with trimesoyl chloride. The quaternary ammonium and spiral conformation of the monomer confer more positive charge and free volume to the membrane, leading to one of the highest permeance (~22 L m⁻² h⁻¹ bar⁻¹) compared to the state-of-the-art Mg²⁺/Li⁺ nanofiltration membranes. Meanwhile, membrane structures are chlorine resistant as the amine–acyl bonding contains no sensitive N-H group. Thus the high performance of membrane is stable versus 400-h immersion in sodium hypochlorite, while control membranes degraded readily. Molecular simulations show that the high permeance and chlorine resistance, which were reproducible at the membrane module level, arise from the spiral conformation and secondary amine structures of the monomer.

目前的聚酰胺提锂纳滤膜容易受到氯降解和/或渗透性低的影响，这是两个难以解决的问题。在这里，我们通过设计季铵化螺哌嗪单体并通过与均苯三甲酰氯的界面聚合将其有益特性转化为大面积膜（1 × 2 m ^{2 ），同时规避了这些问题。}单体的季铵和螺旋构象赋予膜更多的正电荷和自由体积，与现有技术相比，具有最高的渗透率之一（〜22 L m ^-2 h ^-1 bar ^-1 ） art Mg ²⁺ /Li ⁺纳滤膜。同时，膜结构具有耐氯性，因为胺-酰基键不含敏感的 NH 基团。因此，与在次氯酸钠中浸泡 400 小时相比，膜的高性能是稳定的，而对照膜则容易降解。分子模拟表明，在膜组件水平上可重现的高渗透性和耐氯性源于单体的螺旋构象和仲胺结构。