Electrochemical Studies on the Passive Film Integrity of Titanium Under Seawater Biofilms

An attempt was made to explore the electrochemical behavior of Titanium (Ti) condenser material under seawater biofilms. The Ti specimens with seawater biofilm were subjected to microscopic examinations and electrochemical studies such as cyclic voltammetry (CV), electrochemical impedance spectroscopy, open circuit potential monitoring and anodic polarization. The CV curves of Ti specimens with 15 days old biofilms showed characteristic redox peaks with high cathodic current indicating the electroactive biofilms. Similarly impedance spectra clearly showed two time constants with decrease in charge transfer resistance and increase in capacitance as the biofilms growth increased on the Ti specimens. Polarization curve showed the ennoblement of corrosion potential and increase in passive current with the growth of biofilm on Ti. Based on these data, a possibility of Ti passive film integrity loss by electroactive seawater biofilms has been discussed.