Effect of Potential, Temperature, and Fluoride Ions on the Repassivation Kinetics of Titanium in Phosphate Buffered Saline Solution with the Photon Rupture Method

The effect of the applied potentials, temperature, and F− ions on the localized repassivation kinetics of titanium was investigated by the photon rupture method, PRM, and electrochemical techniques in phosphate buffered saline solution. The log⁡ I versus log⁡ t plots after laser beam irradiation showed a rapid increase, then a decrease with a slope of about −1.5 , which is steeper than that expected from high field oxide film formation theory, suggesting that the repassivation of titanium is a combination of electrochemical and chemical reactions. The repassivation current increases with increases in the applied potential and addition of F− ions, while solution temperature does not influence the repassivation kinetics. The effect of F− ions on the repassivation kinetics can be explained by localized pH changes caused by very rapid dissolution of titanium when titanium was exposed to PBS solution.