Removing an Air Layer from a Superhydrophobic Surface in Flowing Water

Abstract The removal of a surface air layer from a superhydrophobic coating in flowing water was evaluated using a laser beam and a high-speed camera. It proceeded via three steps: (1) removal of the top unstable air layer, (2) retention of air in the bottom of the surface microstructure, and (3) replacement of air in the microstructure with water. Different flow velocities result in different removal rates of the surface air layer.