Surface characteristics of Zinc–TiO₂coatings prepared via micro-arc oxidation

Titanium (Ti) and its alloys are widely used as metallic biomaterials for fabrication of dental and orthopedic implants due to their favorable biocompatibility and corrosion resistance in a body environment. However, the thin oxide layer (TiO2) on Ti substrate formed naturally in air or in many aqueous environments is bioinert and surrounded by fibrous tissues without producing any chemical or biological bond to bone when implanted. In the present work, Zinc-incorporated porous TiO2 coatings (Zn–TiO2) were prepared on Ti substrate by micro-arc oxidation (MAO) technique in the zinc gluconate-containing electrolyte. The surface morphology, cross-sectional morphology, composition, and phase of the coatings were analyzed using scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffractometry, respectively. Surface topography and roughness of the coatings were investigated by atomic force microscopy operated in tapping mode. The results showed that Zn was successfully incorporated into the porous TiO2 coatings, which did not alter apparently its surface topography and phase composition. In conclusion, the formation of porous Zn–TiO2 coatings endow Ti with potential bioactivity and antibacterial activity, and we believe that the porous Zn–TiO2 coatings on Ti by MAO technique might be promising candidates for orthopedic and dental implants