Electrochemical characterization of innovative hybrid coatings for metallic artefacts

In this paper, an electrochemical characterization of two different hybrid coatings is presented, with the specific aim of studying their corrosion protection behavior and better understanding their possible application in the cultural heritage field. The two formulations under study were epoxy resin containing silica nanoparticles and epoxy resin containing graphene oxide. Electrochemical Impedance Spectroscopy (EIS) and Scanning ElectroChemical Microscopy (SECM) were used to compare the electrochemical behavior of the two coatings and highlight their failure mechanism when immersed in an electrolytic solution containing chlorides. The investigation highlighted the good corrosion protective properties of both coatings; and moreover, thanks to the joined use of the two described analytical techniques, the different water uptake of the two solutions was studied, together with the different evolution of the coating surface morphology when immersed in the electrolytic solution.