The superhydrophobic properties of ZrO2 induced by laser irradiation

The stable superhydrophobic surface of the ZrO₂ substrate could be conveniently and rapidly prepared by KrF laser irradiation. With different laser energy density, the static water contact angle (CA) increased from 72° to approximately 151°. It was found that the formation of micro–nano fluctuant geometry surface structure was the dominant factor to the hydrophobic property after laser irradiation. When the laser‐irradiated sample annealed at O₂ atmosphere, formation of oxygen‐related defects with high surface free energy could make the CA decrease abruptly at the beginning. After being stored at ambient atmosphere, the CA would reconvert to the value of the freshly irradiated sample gradually. Copyright © 2012 John Wiley & Sons, Ltd.