Structural characteristics and barrier properties of anodic zirconium oxides for biomedical applications

A. GOMEZ SANCHEZ; KATUNAR, M.R; CERE, SILVIA

Nanostructured Anodic Metal Oxides: Synthesis and Applications

Elsevier

Año: 2019;

Originally used almost exclusively as a nuclear material due to its low neutron absorption section, zirconium and some of its alloys are currently being a high-quality alternative to titanium as permanent implant material. Zirconium belongs to the group of ?valve metals?, characterized by the rapid irreversible formation in oxygenated media of a surface oxide film which behaves as a barrier against corrosion in many aggressive media including living tissue fluids. Anodization represents an inexpensive and efficient route to re-design the surface of zirconium in the micro and nanoscale. In acidic media, the thickening of zirconium oxide layer may be controlled by the anodic potential. When fluorides are present in the anodizing electrolyte, ordered nanotubular structures may be formed. Thus, the carefully selection of anodization conditions lead to a wide range of morphologies including nanopores and high aspect ratio nanotubular structures. Some difficulties, however, are still unsolved, as the adhesion of thick nanotubular oxide layers to the metal substrate, or homogeneous coverage on complex geometries. In this chapter, current results regarding structure and surface characteristics influence on the in vitro and in vivo performance of anodised zirconium and alloys will be reviewed and some trends for further research will be stated.