Wettability-controllable super water- and moderately oil-repellent surface fabricated by wet chemical etching.

A facile fabrication method is presented for a super-repellent surface, in which a silicon wafer is etched with a wet chemical method and treated by a fluorinated self-assembled monolayer. This surface is composed of harshly rough nanostructures and highly dense nanoholes. The contact angle of both water and oil with the surface is larger than 150 degrees. The self-cleaning capability of the surface allows for the removal of sticky powders with glycerin droplet. Any desired part(s) of the super-repellent surface can be turned superamphiphilic by simply exposing the desired part(s) to ultraviolet light.