Abstract Stimuli-responsive membranes have been widely explored to mitigate fouling on the membrane surface to achieve the stable performance of water purification. Herein, a facile one-step coating of photo-mobile materials on membrane surface was developed to impart self-cleaning property upon exposure alternatively to ultraviolet (UV) and visible light. Specifically, photo-mobile 4,4′-azodianiline (AZO) and a bio-adhesive polydopamine (PDA) were co-deposited on the surface of ultrafiltration (UF) membranes. The effect of the coating layer on the surface hydrophilicity and pure water permeance was systematically evaluated. The photoresponsive properties of AZO in solutions and thin films with PDA was characterized using UV–Vis absorption spectroscopy. When exposed with UV light, AZO undergoes photoisomerization from trans-AZO to cis-AZO, decreasing the volume, while the exposure to visible light enables the transition from the cis- to trans- configuration, increasing the volume. The resulted self-cleaning behavior of the modified membranes through the reversible volume change is demonstrated in treating 1 g/L bovine serum albumin (BSA) solution. After exposure to the alternative UV/vis light, the AZO-coated UF membranes showed an increased water permeance by ~160%.

中文翻译：

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通过光移动性 4,4'-偶氮二苯胺和生物粘合剂聚多巴胺的共沉积用于水净化的自清洁膜

摘要 刺激响应膜已被广泛探索以减轻膜表面的污染，从而实现稳定的水净化性能。在此，开发了一种在膜表面上简单的一步式光迁移材料涂层，以在交替暴露于紫外线 (UV) 和可见光时赋予自清洁性能。具体而言，将光迁移 4,4'-偶氮二苯胺 (AZO) 和生物粘附性聚多巴胺 (PDA) 共沉积在超滤 (UF) 膜的表面。系统评价了涂层对表面亲水性和纯水渗透性的影响。AZO 在溶液和 PDA 薄膜中的光响应特性通过紫外-可见吸收光谱表征。当暴露在紫外光下时，偶氮经历从反式偶氮到顺偶氮的光异构化，减少体积，而暴露于可见光使顺式构型转变为反式构型，从而增加了体积。在处理 1 g/L 牛血清白蛋白 (BSA) 溶液时证明了改性膜通过可逆体积变化产生的自清洁行为。在暴露于替代的 UV/vis 光后，AZO 涂层的 UF 膜的水渗透性增加了约 160%。