Surface modification with hierarchical CuO arrays toward a flexible, durable superhydrophobic and self-cleaning material

Abstract

A simple hydrothermal method is reported here to in-situ fabricate hierarchical CuO spheres on polyimide (PI). After introducing a coating layer of low surface energy, superhydrophobicity is imparted to resultant films, where the wetting state of water droplet can be well-controlled by simply adjusting the micro/nano-structures of CuO. Particularly, the superhydrophobic surface can resist acid- and base-corrosion, high and low temperatures, flushing and ultrasonication, showing high durability against these extreme treatments. In addition, the film has a self-cleaning property toward organic and inorganic dusts. We believe the superhydrophobic and flexible PI films with self-cleaning function are of great interest to practical outdoor applications.