Effects of varying graphene nanoplates addition on anticorrosive properties of graphene nanoplates-40%Zn/epoxy coating

Different mass ratios of graphene nanoplates (G_nps) were added into Zn/epoxy (EP) coatings with 40%Zn content to prepare G_nps-40%Zn/EP composite coatings. The Zn/EP coating with 70%Zn content was also prepared as the contrast. The Raman spectra, SEM, salt spray test and electrochemical technique et al were applied to evaluate the barrier property and cathodic protection effect of G_nps-40%Zn/EP composite coatings. The anticorrosive effects of G_nps-40%Zn/EP composite coatings and 70%Zn/EP coating were compared to explore the possibility of reducing Zn content by adding G_nps into Zn/EP coating. To further clarify anticorrosive mechanism of Zn/EP coating with varying G_nps addition, the anticorrosive model was established. The results indicate that G_nps could be well-dispersed into Zn/EP coatings, but disorder parameter of G_nps increases with the increasing of G_nps addition. While G_nps addition are 0.3%, 0.5% and 1.0%, the physical shielding performance of Zn/EP coating can be significantly improved; while G_nps addition are 0.5% and 1.0%, the cathodic protection effect of Zn/EP coatings can be significantly enhanced; While G_nps addition is 1.5%, both shielding performance and cathodic protection effect of Zn/EP coatings are not obviously improved. For G_nps-40%Zn/EP composite coating, the best addition range of G_nps is 0.5%-1.0%. The suitable addition of G_nps can reduce Zn content in Zn/EP coating and lower the production cost.