The electrical neutrality of ionic liquids (ILs) was exploited to enhance the antifouling property of polyamide (PA) reverse osmosis (RO) membranes in this work. We solely tethered the aminated imidazolium cation of ILs [AVIM] Br onto the top-surface of PA RO membranes via mild amidation. The molecular simulation results confirmed that the tethered imidazolium cation and the dissociated bromine anion were stably existed in the form of ion pairs on PA RO membrane surface. In virtue of the electrical neutrality of these ion pairs, the ionic-solvation induced hydration layer formed in ILs above the modified membrane surface was thick and evenly distributed, similar to that formed in conventionally electroneutral zwitterion antifouling materials. Thereby, the cation-tethered membrane surface intuitively achieved balanced charge and strong hydrophilicity, and stably exhibited low protein adsorption and excellent antifouling behaviors to diverse foulants, even when the imidazolium cation was paired with anions of different molecular size. Meanwhile, the typical ridge-and-valley surface morphology for PA RO membrane was well preserved due to the mild modification condition, and thereby harvested satisfactory separation performance. The integration of high performance, abundant ILs and mild conditions was expected to expand the application of superb antifouling materials in a variety of biofouling areas.

在这项工作中，利用离子液体 (IL) 的电中性来增强聚酰胺 (PA) 反渗透 (RO) 膜的防污性能。我们仅将 ILs [AVIM] Br 的胺化咪唑鎓阳离子通过轻度酰胺化。分子模拟结果证实，束缚的咪唑鎓阳离子和解离的溴阴离子以离子对的形式稳定存在于 PA RO 膜表面。由于这些离子对的电中性，在改性膜表面上方的离子液体中形成的离子溶剂化诱导的水合层很厚且分布均匀，类似于在常规电中性两性离子防污材料中形成的水​​合层。因此，阳离子系膜表面直观地实现了电荷平衡和强亲水性，即使咪唑鎓阳离子与不同分子大小的阴离子配对，也能稳定地表现出低蛋白质吸附和对各种污染物的优异防污性能。同时，由于温和的改性条件，PA RO膜的典型脊谷表面形态得到了很好的保留，从而获得了令人满意的分离性能。高性能、丰富的 ILs 和温和条件的结合有望扩大优良防污材料在各种生物污垢领域的应用。