Anticorrosion performance of Zn-Al-Gr/waterborne epoxy composite coatings on mild steel

Graphene (Gr) has attracted much attention due to its excellent performance. There are various studies about Gr composite materials; however, the influence of Gr on anticorrosion mechanism was not explored widely. In this paper, the Gr was prepared by oxidation-reduction method and was modified with 3-aminopropyl triethoxysilane for better dispersion. Fourier Transform Infrared Spectroscopy (FT-IR) and Scanning Electron Micrograph (SEM) were utilized to characterize the microstructure of coating and the modification of Gr. X-Ray Diffraction (XRD) was employed to analyse the phase composition of the coating. The anticorrosion performance of coating was investigated by employing polarization curves and electrochemical impedance spectroscopy (EIS). The results showed that the uniformly dispersed Gr nanosheets in Zn-Al-Gr/waterborne epoxy enhanced the protection property of the composite coating. Furthermore, the corrosion resistance properties of the composite coating were optimized by tuning the concentration of the added Gr.