Chemically modified superhydrophobic WO(x) nanowire arrays and UV photopatterning

A facile route is reported for the fabrication of superhydrophobic tungsten oxide (WO(x)) nanowire surfaces through the chemical adsorption of alkyltrichlorosilane with a static water contact angle (CA) of 163.5 degrees. It is confirmed that CAs on the superhydrophobic surface decreased gradually under UV illumination because of the UV-assisted decomposition of alkyltrichlorosilane chemically adsorbed onto the surface. Superhydrophobic-superhydrophilic switching is also demonstrated by alternating self-assembled monolayer deposition and UV irradiation on the photopatterned nanowire surfaces. Furthermore, the superhydrophobic surface could be transformed selectively into a hydrophilic state by simply exposing the surface to UV through a shadow mask. These studies provide a relatively simple strategy for the design of superhydrophobic surfaces.