Ultraviolet-enhanced bioactivity of ZrO2 films prepared by micro-arc oxidation

Macroporous and nano-crystallized monoclinic zirconia (m-ZrO2) film was prepared by micro-arc oxidation (MAO). The effect of ultraviolet (UV) irradiation on the microstructure, water contact angle and bioactivity of the film were investigated. The MAO-formed ZrO2 film exhibits high hardness and elastic modulus. UV irradiation of the ZrO2 film does not alter surface morphology, grain size and phase component, however, can significantly improve hydrophilicity and bioactivity of the film. The enhanced hydrophilicity and bioactivity are thought to result from the abundant basic Zr–OH groups on the UV-irradiated film, which have relative long-term stability.