Superwetting Materials of Oil–Water Emulsion Separation

Abstract With industrial development and population expansion, the problem of water pollution has intensified. The purification of oily water, especially oil–water emulsions, is one of the important topics of environment protection. Traditional filter membranes, to some extent, are useful for the separations of oil–water mixtures but suffer from many limitations and there is no effective way to achieve emulsified oil–water separation. Superwetting materials, based on bionics, have opened a brand-new door to membrane separation techniques. The rise and maturation of nanometer-scale materials also injects new vigor into this research area. In this paper, we review the contributions to oil–water emulsion separation in recent literatures. The principles of superwetting materials in separation of oil–water mixtures have been briefly stated at first. Some classical and latest examples, as well as some great work by our group, have been emphasized. Section 3 is the key point of this article. It covers the most valuable of recent progresses in advanced materials for oil–water emulsion separation, from novel polymer membranes to nanomaterial-based membranes. Of course, special-wettability materials and non-two-dimensional separation methods have also been instructive. The aim of the optimal design of superwetting membranes is to make future researches theoretical, instructive, and practical. Finally, some challenges and the potential promising breakthroughs in this field are also succinctly highlighted.