Yang Yong, Guo Zhiguang, Liu Weimin
Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei University, Wuhan, 430062, P. R. China.
State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, P. R. China.
Small. 2022 Dec;18(48):e2204624. doi: 10.1002/smll.202204624. Epub 2022 Oct 3.
Since superwetting surfaces have emerged, on-demand oil/water separation materials serve as a new direction for meeting practical needs. This new separation mode uses a single porous material to allow oil-removing and water-removing to be achieved alternately. In this review, the fundamentals of wettability are systematically summarized in oil/water separation. Most importantly, the two states, bioinspired surface and intelligent surface, are summarized for on-demand oil/water separation. Specifically, bioinspired surfaces include micro/nanostructures, bioinspired chemistry, Janus-featured surfaces, and dual-superlyophobic surfaces that these superwetting materials can possess asymmetric wettability in one structure system or opposite underliquid wettability by prewetting. Furthermore, an intelligent surface can be adopted by various triggers such as pH, thermal and photo stimuli, etc., to control wettability for switchable oil/water separation reversibly, expressing a thought beyond nature to realize innovative oil/water separation by external stimuli. Remarkably, this review also discusses the advantages of all the materials mentioned above, expanding the separation scope from the on-demand oil/water mixtures to the multiphase immiscible liquid-liquid mixtures. Finally, the prospects of on-demand oil/water separation materials are also concluded.
自从超润湿表面出现以来，按需油/水分离材料成为满足实际需求的一个新方向。这种新的分离模式使用单一的多孔材料，使除油和除水能够交替实现。在这篇综述中，系统总结了油/水分离中润湿性的基本原理。最重要的是，总结了用于按需油/水分离的两种状态，即仿生表面和智能表面。具体而言，仿生表面包括微/纳米结构、仿生化学、具有Janus特性的表面以及双超疏水表面，这些超润湿材料在一个结构系统中可具有不对称润湿性，或通过预润湿具有相反的水下润湿性。此外，智能表面可采用各种触发因素，如pH值、热和光刺激等，来可逆地控制润湿性以实现可切换的油/水分离，表达了超越自然的想法，通过外部刺激实现创新的油/水分离。值得注意的是，本综述还讨论了上述所有材料的优点，将分离范围从按需油/水混合物扩展到多相不混溶液-液混合物。最后，还总结了按需油/水分离材料的前景。
