An electrochemical investigation of the effect of nano sized TiO۲particales on cathodicdisbonding of epoxy-polyaniline coated mild steel

Corrosion of metals is an enormous problem throughout the world. Several techniques have been used to protect metals from corrosion. Among them, the use of organic coatings in conjunction with cathodic protection is considered efficient apporoach to combat corrosion. Although the combination offers various merits, the serious problem called cathodicdisbondment could be raised in the presence of failures on the protective coatings[۱]. The applied cathodic potential that activates cathodic reactions at the adge of the defects is the driving force for this phenomenon. In fact, cathodic disbanding as a consequence of cathodic protection occurs due to hydrogen evolution and accumulation of OH- ions at the coating- substrate interface[۲].Attempts have been made to use corrosion pigments to imorove the cathodic disbonding resistance of the organic coatings.In recent years, attempts have been done to use nano sized anticorrosion pigments to improve the coating resistance against cathodic disbanding[۳]. Electrochemical Impedance Spectroscopy (EIS) has taken an undeniable position in corrosion studies. EIS is considered a powerful nondestructive test to evaluate performance of the protective coatings[۴].The scope of this work is to study the effect of TiO۲ nanoparticles addition on the resistance of epoxy- polyaniline (EP-PANI) coating to cathodic disbanding via EIS. Further investigation was facilitated usig surface analysis.

کلیدواژه ها:

Cathodic disbanding ، TiO۲ nanoparticles ، Epoxy- polyaniline coating ، EIS