Production and characterization of TiO2 nanotubes on Ti-Nb-Mo-Sn system for biomedical applications

Nanotube layers with different morphological characteristics were successfully grown on a Ti-30Nb-4Sn substrate with the gradual addition of Mo. Although the martensitic phase was suppressed during rapid cooling due to the addition of Mo, all the compositions presented a low elastic modulus, which favors their biomedical uses. In this study, the effects of anodizing parameters, substrate roughness, and alloy composition were investigated. The process parameters were first optimized, after which the morphology, crystallization parameters, and wettability of the nanotubes were evaluated. The results indicate that the addition of Mo increased the length of the nanotubes and decreased their inner and outer diameters. The polished substrate favored the homogeneity of the nanotube layers. In addition, the Mo content delayed the anatase-to-rutile transformation, which altered the hydrophilicity of the anodized alloys.