title: Facile synthesis of superhydrophobic surface of ZnO nanoflakes: chemical coating and UV-induced wettability conversion.
abstract: This work reports an oriented growth process of two-dimensional (2D) ZnO nanoflakes on aluminum substrate through a low temperature hydrothermal technique and proposes the preliminary growth mechanism. A bionic superhydrophobic surface with excellent corrosion protection over a wide pH range in both acidic and alkaline solutions was constructed by a chemical coating treatment with stearic acid (SA) molecules on ZnO nanoflakes. It is found that the superhydrophobic surface of ZnO nanoflake arrays shows a maximum water contact angle (CA) of 157° and a low sliding angle of 8°, and it can be reversibly switched to its initial superhydrophilic state under ultraviolet (UV) irradiation, which is due to the UV-induced decomposition of the coated SA molecules. This study is significant for simple and inexpensive building of large-scale 2D ZnO nanoflake arrays with special wettability which can extend the applications of ZnO films to many other important fields.
authors.affiliation: Laboratory of Condensed Matter Spectroscopy and Opto-Electronic Physics, and Key laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China. mjzheng@sjtu.edu.cn.
authors.forename: Lujun
authors.initials: L
authors.lastname: Yao
authors.forename: Maojun
authors.initials: M
authors.lastname: Zheng
authors.forename: Changli
authors.initials: C
authors.lastname: Li
authors.forename: Li
authors.initials: L
authors.lastname: Ma
authors.forename: Wenzhong
authors.initials: W
authors.lastname: Shen