Reversible surface wettability transition between superhydrophobicity and superhydrophilicity on hierarchical micro/nanostructure ZnO mesh films

Large-area ZnO nanorod arrays were synthesized successfully on the stainless steel mesh through chemical vapor deposition route. The coated mesh shows good water permeability after ultraviolet (UV) irradiation, while it is impermeable to water after dark storage. This repeatable process suggests that the wettability transition of the rough surface is complete reversible. Besides, the special hierarchical nanostructures and the suitable size of the original mesh play an important role in smart controllability of the water permeability. The reversible transition of surface wettability has potential applications in many aspects, such as microchips, micro-fluidic devices, and biotechnology.