Microstructure, Wettability, Corrosion Resistance and Antibacterial Property of Cu-MTa₂O₅ Multilayer Composite...

Bacterial infection and toxic metal ions releasing are the challenges in the clinical application of Ti6Al4V alloy implant materials. Copper is a kind of long-acting, broad-spectrum and safe antibacterial element, and Ta₂O₅ has good corrosion resistance, wear-resistance and biocompatibility, they are considered and chosen as a potential coating candidate for implant surface modification. In this paper, magnetron sputtering technology was used to prepare copper doped Ta₂O₅ multilayer composite coating Cu-Ta₂O₅/Ta₂O₅/Ta₂O₅-TiO₂/TiO₂/Ti (Cu-MTa₂O₅ for short) on Ti6Al4V alloy surface, for studying the effect of copper incorporation on the microstructure, wettability, anticorrosion and antibacterial activities of the composite coating. The results showed that Cu-MTa₂O₅ coating obviously improves the hydrophobicity, corrosion resistance and antibacterial property of Ti6Al4V alloy. In the coating, both copper and Ta₂O₅ exhibit an amorphous structure and copper mainly presents as an oxidation state (Cu₂O and CuO). With the increase of the doping amount of copper, the grain size, roughness, and hydrophobicity of the modified surface of Ti6Al4V alloy are increased. Electrochemical experiment results demonstrated that the corrosion resistance of Cu-MTa₂O₅ coated Ti6Al4V alloy slightly decreased with the increase of copper concentration, but this coating still acts strong anticorrosion protection for Ti6Al4V alloy. Moreover, the Cu-MTa₂O₅ coating can kill more than 97% of Staphylococcus aureus in 24 h, and the antibacterial rate increases with the increase of copper content. Therefore, Cu-MTa₂O₅ composite coating is a good candidate for improving anticorrosion and antibacterial properties of Ti6Al4V alloy implant medical devices.