Abstract
The kinetics of film growth and concomitant dissolution of titanium repassivating in alkaline methanolic solutions containing small amounts of water are described. The early stages of anodic film growth consist of the random oxidation of exposed metal atoms; the rate constant describing this process is independent of electrode potential and is first order in water activity, with 
. The rate constant for simultaneous metal dissolution is independent of water activity, but depends exponentially on potential. Subsequent film thickening occurs by oxide film growth under high electric field, but the rate of film growth is controlled by the rate of access of water, allowing an excess of metal cations at the oxide/electrolyte interface to dissolve. Final repassivation ensues by high field ion conduction at 100% current efficiency only when the rate of ion migration through the film falls below that capable of reacting with water. The rate constants are presented.