Dynamic Effects of Bouncing Water Droplets on Superhydrophobic Tungsten Oxide nanowire surfaces

The effects of surface energyon the wetting transition for impinging water droplets were experimentally investigated on the chemically modified WOx nanowire surfaces. We could modify the surface energy of the nanostructures through chemisorption of alkyltrichlorosilanes with various carbon chain lengths and by the UV-enhanced decomposition of self assembled monolayer (SAM) molecules chemically adsorbedon the array. Three surface wetting states could be identified through the balance between antiwetting and wetting pressures. This approach establishes simple strategy for the design criteria for water-repellent surface to impinging droplets.