A fast and effective approach for reversible wetting-dewetting transitions on ZnO nanowires

作者：Yadav Kavita; Mehta B R; Bhattacharya Saswata; Singh J P

来源：Scientific Reports, 2016, 6(1): 35073.

DOI：10.1038/srep35073

<jats:title>Abstract</jats:title><jats:p>Here, we demonstrate a facile approach for the preparation of ZnO nanowires (NWs) 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 NWs obtained by a chemical vapor deposition method are superhydrophilic with a contact angle (CA) value of ~0°. After H<jats:sub>2</jats:sub> gas annealing at 300 °C for 90 minutes, ZnO NWs display superhydrophobic behavior with a roll-off angle less than 5°. However, O<jats:sub>2</jats:sub> gas annealing converts these superhydrophobic ZnO NWs into a superhydrophilic state. For switching from superhydrophobic to superhydrophilic state and vice versa in cyclic manner, H<jats:sub>2</jats:sub> and O<jats:sub>2</jats:sub> gas annealing treatment was used, respectively. A model based on density functional theory indicates that the oxygen-related defects are responsible for CA switching. The water resistant properties of the ZnO NWs coating is found to be durable and can be applied to a variety of substrates including glass, metals, semiconductors, paper and even flexible polymers.</jats:p>

• 出版日期2016-10-7