Waterborne acrylic paint system based on nanoceria for corrosion protection of steel

The corrosion protection efficiency of steel painted with waterborne acrylic coatings loaded with diverse concentration of cerium oxide nanoparticles are presented in this paper. The investigation was carried out by means of Electrochemical Impedance Spectroscopy (EIS) and the salt spray test. EIS has been conducted at two experimental conditions: the intact coating condition as well as in presence of a purposely created macroscopic defect. EIS observations from the intact coatings evidenced the higher protection for the paint systems containing the ceria nanoparticles compared to that without the nanoceria, e.g. higher magnitudes for the charge transfer resistance after certain period of exposure to sodium chloride solution. In addition to that, from the evolution of the double layer capacitance on the defected coatings condition, reduced delamination rates were perceived for those containing 0.5 and 1.0 wt.% of nanoceria. Similarly, after exposure to the salt spray test a reduced delaminated area was suggested for 0.5, 1.0 and 2.0 wt.% compared to that without nanoceria. Generally, a beneficial contribution of nanoceria into an acrylic waterborne paint system on the corrosive protection of steel was found and the optimal concentration of nanoceria associated to higher corrosion protection was verified for the paint system containing 1.0 wt.%.