Recent development of super-wettable materials and their applications in oil-water separation

Offshore oil spills and the discharge of oily effluents are not only damaging the economy but also disturbs our aquatic and biotic environment. Since, the discovery of super-wetting properties from natural phenomena, experts have designed and developed different kinds of super-wettable materials to be used for self-cleaning, anti-icing, anti-fogging, water collection and the oil-water separation. In particular, various types of super-wettable materials are being developed in order to better separate oil from contaminated water. Therefore, the present review is designed to highlight recent advances in super-wettable materials including classification, synthesis methods and their applications. Also, the research progress on super-wettable oil-water separation materials is described in detail, and categorized into three segments: (i) superhydrophobic-superoleophilic materials; (ii) superhydrophilic-superoleophobic materials; (iii) smart responsive wettability materials. Finally, the major issues and challenges associated with the application of super-wettable materials in the oil-water separation system are highlighted to understand better the research gap and limitations in the marketing of these materials. Moreover, we believe that large scale development of cost effective, stable, green and practically applicable super-wettable oil-water separation materials has bright future.