Designing durable and flexible superhydrophobic coatings and its application in oil purification

Abstract

Lotus-inspired superhydrophobic coatings are usually mechanically weak and lack durability, this hinders their practical applications. A suspension that can be treated on various materials in any size and shape to form a mechanically durable superhydrophobic coating is developed, which retains water repellent properties after multiple cycles of abrasion, blade scratching, tape-peeling, repeated deformation, a series of environmental tests and recycling. Based on its superhydrophobicity under oil, two highly efficient systems were developed for oil purification – stirring and inverted cone systems. Small water drops converge on the coated surface that was immersed in oil through velocity-controlled stirring, or designing an inverted cone superhydrophobic surface under oil to collect water drops spontaneously. This coating can be readily used for practical applications to make a durable superhydrophobic coating that functions either in air or oils.