On the potential of CeO2 nanoparticles as corrosion inhibitor in waterborne acrylic coatings

Ceria nano-particles (synthesized via a wet-chemical precipitation) were incorporated into a water based acrylic binder at diverse concentration levels (0.5, 1.0, 2.0 and 3.0 wt%). 10 µm thick coatings were applied onto cold rolled steel using a blade. A clear-coat waterborne acrylic binder was produced for comparison. The protection properties of the different coatings were investigated by means of electrochemical impedance spectroscopy (EIS), both on intact and scratched coatings. Similarly, exposure in neutral salt spray chamber was carried out both on intact and scratched samples. The experimental results suggested that the presence of the ceria nanoparticles promotes a certain inhibitive effect reducing the delamination rate of the coating from the substrate. In particular, from EIS measurements and neutral salt spray test it has been observed lower delamination rates as well as lower quantities of blisters for the paint systems containing 0.5 and 1.0 wt% of CeO2.