Cathodic Electrodeposion of Nanotitania along with the Epoxy Based Coating and Evaluation of its Anticorrosion Properties

The effect of nano-TiO2 particles on the corrosion properties of epoxy based coatings was investigated so that the nano titania particles were co-deposited together with epoxy resins on standard phosphated steel panels by cathodic electrodeposition technique. To evaluate its anticorrosion properties, the coating containing nano titania were compared with plain coating regarding to their immersion stability in 3.5% NaCl solution for 2880 hours (120 days). The scanning electron microscopy micrographs showed that the nano titania particles were dispersed appropriately within the coatings. Moreover, electrodeposition process was performed at a pH value of about 6.0 which lies below the isoelectric point of nano titania for the nano titania could be electrodeposited cathodic. The electrochemical impedance spectroscopy technique was used to investigate the corrosion properties of coatings. The resulted Nyquist graphs and Bode plots showed that the high corrosion resistance of the nano titania has caused an improvement in the correlating epoxy layers even after 120 days of immersing in 3.5% NaCl solution.