Self-organizing evolution of anodized oxide films on Ti-25Nb-3Mo-2Sn-3Zr alloy and hydrophilicity

Abstract

In the present work, hierarchical nanostructured titanium dioxide (TiO₂) films were fabricated on Ti-25Nb-3Mo-2Sn-3Zr (TLM) alloy for biomedical applications via one-step anodization process in ethylene glycolbased electrolyte containing 0.5wt% NH₄F. The nanostructured TiO₂ films exhibited three distinct types depending on the anodization time: top irregular nanopores (INP)/beneath regular nanopores (RNP), top INP/middle regular nanotubes (RNT)/bottom RNP and top RNT with underlying RNP. The evolution of the nanostructured TiO₂ films with anodization time demonstrated that self-organizing nanopores formed at the very beginning and individual nanotubes originated from underlying nanopore dissolution. Furthermore, a mod`ified two-stage self-organizing mechanism was introduced to illustrate the growth of the nanostructured TiO₂ films. Compared with TLM titanium alloy matrix, the TiO₂ films with special nano-structure hold better hydrophilicity and higher specific surface area, which lays the foundation for their biomedical applications.

Keywords

Ti-25Nb-3Mo-2Sn-3Zr alloy / hierarchical nanostructured oxide layers / anodization / hydrophilicity

References

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