Abstract Construction of zero-flux-decline membrane surfaces with superior antifouling properties is in great demand for the treatment of oil-water mixture. Inspired by nature, simultaneously incorporating hydrophilic and low-surface-energy groups to form a chemically heterogeneous hydrogel surface holds great promise. In this study, membranes with heterogeneous hydrogel surfaces were fabricated through a one-step reaction enhanced surface segregation method. In details, we synthesized a fluorine-containing copolymer as the modifier in casting solution, and designed tannic acid (TA) aqueous solution as the coagulation bath. During non-solvent induced phase separation, TA can in situ crosslink the modifier at the water-polymer interface through hydrogen bonds, forming a heterogeneous hydrogel layer over the membrane surface. Meanwhile, the hydrophilicity of TA rendered the hydrogel underwater superoleophobic properties. The thickness and chemical composition of the hydrogel layer were facilely manipulated by varying the TA concentration. To our surprise, the unique physicochemical characteristics of heterogeneous hydrogel layer greatly fortified the antifouling mechanisms on membrane surfaces, rendering the membrane zero-flux-decline feature with a flux of 330 L m−2 h−1 at 0.05 MPa during a 60-h cross-flow filtration of five different oil-in-water emulsions.

中文翻译：

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用于油水分离的近零通量下降膜的化学异质水凝胶表面的原位构建

摘要 构建具有优异防污性能的零通量递减膜表面是处理油水混合物的迫切需求。受大自然的启发，同时结合亲水基团和低表面能基团以形成化学异质水凝胶表面具有广阔的前景。在这项研究中，通过一步反应增强表面分离方法制造了具有异质水凝胶表面的膜。具体而言，我们合成了一种含氟共聚物作为浇铸液中的改性剂，并设计了单宁酸（TA）水溶液作为凝固浴。在非溶剂诱导相分离过程中，TA 可以通过氢键在水-聚合物界面处原位交联改性剂，在膜表面形成异质水凝胶层。同时，TA 的亲水性使水凝胶具有水下超疏油特性。通过改变 TA 浓度可以轻松控制水凝胶层的厚度和化学成分。令我们惊讶的是，异质水凝胶层独特的物理化学特性极大地加强了膜表面的防污机制，使膜零通量下降特征在 60 小时内在 0.05 MPa 下的通量为 330 L m-2 h-1五种不同水包油乳液的错流过滤。