A fast and effective approach for reversible wetting-dewetting transitions on ZnO nanowires
A facile approach for the preparation of ZnO nanowires with tunable surface wettability that can be manipulated reversibly in a controlled manner from a superhydrophilic state to a superhydrophobic state. The as-synthesized ZnO nanowires obtained by a chemical vapor deposition method are superhydrophilic with a contact angle contact angle value of ~0°. After H2 gas annealing at 300 °C for 90 minutes, ZnO nanowires display superhydrophobic behavior with a roll-off angle less than 5°. However, O2 gas annealing converts these superhydrophobic ZnO nanowires into a superhydrophilic state. For switching from superhydrophobic to superhydrophilic state and vice versa in cyclic manner, H2 and O2 gas annealing treatment was used, respectively. The water resistant properties of the ZnO nanowires coating is found to be durable and can be applied to a variety of substrates including glass, metals, semiconductors, paper and even flexible polymers.
Nature Publishing Group
Dr. J.P. Singh, GLAD & nano-CVD lab
Department of Physics