Addition of graphene oxide plates in cataphoretic deposited organic coatings

Abstract

This work aims to verify how the addition of graphene oxide into the cataphoretic bath goes to modify the properties of the obtained coating. Because a simple single-step deposition produced a strange morphology deposit, other combinations consisting of two deposition steps were done, in order to make the coating even more homogeneous and protective. Particular attention is therefore paid to the importance of the intermediate curing process, between the two deposition steps. The morphology of the coatings is analyzed by both optical and scanning electron microscopy, to measure the thickness of the protective layers and their defective properties. Finally, corrosion resistance properties of the coatings are evaluated by salt spray chamber exposure and electrochemical impedance spectroscopy measurements. It appears evident that the graphene oxide leads to the creation of defective layers, with the consequence of decreasing the durability of the coating. However, by depositing in two steps, with two different baths, it is possible to preserve the integrity of the coating, ensuring the protection of the substrate.