Product Code: ICA12_M906

Improving the Wettability on ZnO and ZrO2 Single Crystal Surface by Laser Irradiation
Authors:
Yijian Jiang, Institute of Laser Engineering, Beijing Univ. of Technology; Beijing Peoples Republic of China
Yan Zhao, Institute of Laser Engineering, Beijing University of Technology; Beijing Peoples Republic of China
Sijing Xie, Institute of Laser Engineering, Beijing University of Technology; Beijing Peoples Republic of China
Presented at ICALEO 2012

This paper aims to contribute to the understanding
of laser irradiation effect on the wettability of metal
oxides ZnO and ZrO2. It is shown different behavior
for different crystals. The stable superhydrophobic
surface with the water contact angle (CA) 151° of the
ZrO2 substrate could be rapidly prepared by KrF laser
irradiation. Comparatively, the laser-treated ZnO
sample exhibited hydrophilicity with the CA of 20° at
the first beginning, and after being storage in air for a
while, it turned into final stable hydrophobic state with
CA of 120°. Based on AFM, XPS measurements and
Cassie-Baxter model analysis, it could be concluded
that final hydrophobic states of both ZnO and ZrO2
samples are mainly attributed to the formation of
micro-nano fluctuant geometry structure rather than
the change of surface chemistry. The photoinduced
hydrophilic effect of ZnO is associated with the
hydroxyl absorption on the defective sites induced by
UV laser irradiation.