Fabrication and Wettability Conversion of ZnO/Ag Composite Films

ZnO/Ag composite films were fabricated through sol-gel method. The phases, crystallographic structures and surface topographies of the ZnO/Ag films were characterized by an X-ray diffractometer(XRD) and a scanning electron microscope (SEM). The wettabilities of ZnO/Ag films were characterized by a drop shape analyzer. The effect of Ag content on wettability of ZnO film under UV light was investigated. The result indicated that the molar fraction of Ag loaded on ZnO film had a significant effect on the wettability conversion. A rapid wettability conversion was occurred on ZnO/Ag composite film with Ag content of 5% (molar fraction), which converted hydrophilic after 3 h UV irradiation and returned to superhydrophobic state after stored in a dark place for 5 d. The mechanism for this wettability reversible conversion was discussed.