Abstract
Recently, titanium and titanium alloys with nanotube layers by anodizing process have gained great interests as surgical implant materials. In this paper, the electrochemical stability of TiO2 nanotubue layers prepared by anodization of pure Ti in three solutions has been investigated in simulated biological environment by use of open-circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PD) tests. The PD testing results indicate that the nanotubular Ti shows a slightly higher passivation current than the mechanically polished titanium in Hank's solution, this is attributed to the large surface area created by the nanostructure. Moreover, the electrochemical stability of Ti nanotubes is enhanced, as judged by the more nobler open circuit potential values compared to that of Ti. The dependence of the electrochemical stability of the nanotubular surface depended on the dimensions of the TiO2 nanotube which was controlled by optimizing the anodization electrolyte composition. The results reveal that architecting the surface of titanium on the nanoscale render the surface more biocompatible by creating large surface area and more sustainable by providing more stabilized surface which is less vulnerable to corrosion.