Improved corrosion protection performance of electrophoretic epoxy coatings with the incorporation of amino-functionalized graphene oxide

In this study, polyethyleneimine (PEI) was grafted on the surface of graphene oxide (GO) to prepare PEI-GO material. The PEI-GO/EP composite coating was successfully deposited on carbon steel through the cathodic electrophoretic deposition (C-EPD) process. The zeta potential, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), atomic force microscopy (AFM), and thermogravimetric analysis (TGA) methods were used to characterize the GO and PEI-GO materials. The dispersibility of PEI-GO in epoxy electrophoretic paint was studied by TEM and the fracture surface morphology of the coatings was observed by scanning electron microscope (SEM). Electrochemical impedance spectroscopy (EIS) studies evaluated the corrosion resistance of composite coatings. In summary, the impedance modulus of PEI-GO/EP composite coating is two orders of magnitude higher than that of neat epoxy coating, with enhanced anticorrosion performance.