超浸润油水分离膜及其研究进展

受到自然界中动植物表面超疏水/超亲水特性的启发,仿生超浸润膜材料作为一种新兴的油水分离材料引起了科研人员的广泛关注。首先通过对影响膜材料表面润湿性的基础模型进行分析,包括Young方程、Wenzel模型和Cassie模型,总结了制备超浸润膜材料需要调控的2个关键因素——表面张力和纳微多级结构。其次,对比分析了不同类型超浸润膜的油水分离过程,概述了超浸润油水分离膜的技术优势,包括油水选择性好、分离效率高、操作简单、能耗低等。揭示了常见超浸润膜对稳定油水乳液的分离机理,即基于膜孔径小于乳液尺寸的筛分效应;通过膜材料对油水截然相反的浸润性实现界面破乳和选择性分离。在此基础上,重点综述了近年来常见超浸润油水分离膜的研究进展,其中包括超疏水/超亲油膜、超亲水/水下超疏油膜、Janus膜、智能响应膜,并对不同类型的超浸润膜材料在分离过程中存在的技术优势和问题进行了分析。最后,提出了该领域研究存在的问题和面临的挑战,并对未来超浸润膜材料的发展方向和应用前景进行了展望。

Research Progress of Superwetting Oil-water Separation Membrane

Inspired by the superhydrophobic and superhydrophilic properties of the animal or plant surfaces in nature, biomimetic superwetting membranes as a new kind of oil-water separation material has attracted widespread attention from scientific researchers due to its tremendous development potential and broad application prospects in the field of oil-water separation. The basic theoretical models affecting the surface wettability of membrane materials were discussed by analyzing the Young equation, Wenzel model and Cassie model. The two key factors affecting the preparation of the superwetting membranes were summarized as the surface tension and hierarchical micro/nanostructures. Therefore, the superwetting membranes are fabricated by two main ways:designing nano/micro-hierarchical structures on hydrophobic or hydrophilic surfaces and modifying rough surfaces with low or high surface energy materials. Up to now, various approaches have been reported for the preparation of superwetting membranes, including electrospinning, plasma etching, chemical vapor deposition, solution immersion method, electrochemical deposition, etc.