Superhydrophobic surfaces for oil-water separation

Abstract

Oil spill in the environment is one of the serious issues faced around the world. Efficient oil removal and collection from water is a challenging task. Numerous costly and time-consuming physical, chemical, and biological methods had been adopted for oil spill clean-up. Sponges or membranes having both superhydrophobic and superoleophilic properties can be utilized for easy oil-water separation. On such surfaces, the water droplet attains contact angle greater than 150 degrees (superhydrophobic) and oil droplets quickly get absorbed with contact angle nearly equal to 0 degrees (superoleophilic). The polymer-modified sponges/membranes can selectively absorb the oil and effectively repel the water with high selectivity and recyclability. In addition, the polymeric sponges/membranes can show excellent hydrophobicity, robustness, and flexibility due to the chemical and physical properties of the polymers. Numerous polymer-modified sponges/membranes exhibiting excellent oil absorption capacity, selectivity, recyclability, and mechanical durability are discussed in this chapter. The innovative ideas and methods utilized for the preparation of superhydrophobic sponges/membranes are also reviewed. These smart surfaces can be produced for industrial scale and used for efficient and controlled oil-water separation in high-risk areas.