A strategy of fast reversible wettability changes of WO3 surfaces between superhydrophilicity and superhydrophobicity.
As-prepared WO(3) nanostructure films on alumina or tungsten substrates by a facile hydrothermal method exhibit a superhydrophilic property. An effective strategy is proposed to control the wettability of WO(3) films in a reversible manner between superhydrophilicity and superhydrophobicity with a rapid response. By controlling the process of adsorption/desorption of n-dodecanethiol associated with the light-induced plating Ag nano-grains on WO(3) nanostructures, it only takes about 25 min to fulfill the wettability change from superhydrophilicity to superhydrophobicity, and only 30 s to finish the reversed change. Moreover, the contact angles of WO(3) surface can be tuned by controlling the etching time of superhydrophobic WO(3) surfaces in a solution of nitric acid containing 5 mM sodium dodecyl benzene sulfonate. Electrowetting process is successfully demonstrated to trap a water drop onto the superhydrophobic WO(3) surfaces. Considering WO(3) is one of typical electrochromic materials, researches on the effect of coupling between electrowetting and electrochromic properties would be more promising.
Gu
Changdong
C
Department of Materials Science and Engineering, State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027, China. changdong_gu@hotmail.com
Zhang
Jun
J
Tu
Jiangping
J