Water ultrarepellency induced by nanocolumnar ZnO surface

A surface microtexture comprised of ZnO nanocolumns prepared by a facial cathodic electrode deposition was analyzed. The surface microtexture shows both advancing and receding contact angles (CA) of water higher than 150° after being modified with a monolayer of fluoroalkylsilane (FAS). The columnar surface showed such a small water CA hysteresis that water droplet could not adhered on the surface even placed horizontally. The results show that the ultrahydrophobic ZnO surface can be patterned by UV light, which was more important for a variety of applications such as microchips, microfluidic devices and biotechnology.