Enhancing the Corrosion Resistance of Passivation Films via the Synergistic Effects of Graphene Oxide and Epoxy Resin

Silane-based passivation films have been widely utilized for corrosion protection in metal materials. In order to further improve the anticorrosion performance of the silane passivation film, this paper adopts the hydrolysis method to add graphene oxide (GO) to the silane coupling agent (3-(2,3-glycidoxy)propyltrimethoxysilane) (KH560). The synthesized KH560-GO passivation solution was then mixed with epoxy resin (EP) to prepare a silane composite passivation film layer (KH560-GO/EP) containing GO and epoxy resin. For comparison, EP and KH560-GO films were also prepared, and the corrosion performance of the composite film was compared with that of the single film. The structure of the KH560-GO film was characterized by X-ray diffraction analyzer (XRD) and infrared spectroscopy (FTIR). The microstructure of the composite film was analyzed by scanning electron microscopy (SEM), while its corrosion resistance was tested through polarization curves and electrochemical impedance spectroscopy (EIS). Additionally, neutral salt spray tests were conducted to evaluate the corrosion resistance of the samples, and rubber wiping tests were performed to assess the adhesion of the film. The results demonstrated that the KH560-GO/EP film exhibited a higher corrosion potential (Ecorr) of −0.239 V compared to the EP and KH560-GO films, along with the lowest self-corrosion current density (Icorr) of 6.157 × 10−7 A/cm2. These findings indicate that the KH560-GO/EP film possesses excellent corrosion resistance. The results showed that the corrosion potential (Ecorr) of the KH560-GO/EP film was higher than that of EP and KH560-GO film layer is −0.239 V, and the self-corrosion current density (Icorr) is the smallest, which is 6.157 × 10−7 A/cm2. The KH560-GO/EP film layer shows excellent corrosion resistance. Experiments show that the KH560-GO/EP passivated film has excellent bonding properties and corrosion resistance.