Superhydrophobic Coatings with Periodic Ring Structured Patterns for Self-Cleaning and Oil-Water Separation

Superhydrophobicity induced by surface micro- and nanostructure has many important applications in antisticking, self-cleaning, and oil-water separation. Here, a facile method of fabricating periodic droplet structured patterns on polymer thin films is reported. Once SiO2 nanoparticles are coated on this microstructured film surface, periodic ring structured patterns are formed on the coating surface, which exhibits extremely superhydrophobic behavior with low water adhesion. The water contact angle of the coating can reach up to almost 170 degrees and water droplet can fully rebound from the superhydrophobic surface. This work provides a facile yet robust approach to fabricate superhydrophobic coatings. Moreover, the results show that the coatings can be applicable to self-cleaning and oil-water separation.