Superhydrophobic Coatings for Oil–Water Separation

Frequent oil spills and the continuous discharge of industrial and domestic oily wastewater can significantly affect the economy and aquatic and biotic environments. Scientists have developed extremely water repellent surfaces based on the naturally occurring superhydrophobic surfaces that are widely used in various applications such as oil–water separation, self-cleaning, anti-icing, drag reduction, anti-fouling, anti-fogging and anti-corrosion. Smart materials having the properties of extreme water repellency and oil absorbance have been attracting increasing attention, with promising applications especially in oil–water separation. This chapter is focused on various fabrication techniques that can be used effectively to fabricate superhydrophobic/superoleophilic coatings for efficient oil–water separation. The ongoing research progress in the development of superhydrophobic/superoleophilic coatings on membranes, meshes, sponges and fabrics along with novel oil–water separation methods are discussed. Future prospects and challenges in oil–water separation research are also considered.