Preparation and Anti‐Corrosion Performances of Nano‐ ZnO Modified Graphene Oxide‐Epoxy Resin Composite Coatings

ABSTRACT In this study, graphene oxide (GO) and zinc oxide (ZnO) composite (EPGZnC) coatings were successfully prepared to improve the corrosion resistance of steel. The dispersion effect of GO in epoxy resin (EP) was improved by loading ZnO with three different contents (1/3/5 wt.‰) on the surface of GO. Based on the optimal fill of ZnO (5 wt.‰), the mechanical and corrosion protection properties of EPGZnC were investigated. Combined with microstructure and morphology analysis, the mechanical and corrosion improvement mechanism of 5 wt.‰ ZnO‐GO@EP was revealed. Compared with the resin matrix, the tensile strength and modulus of 3 wt.‰ GO@EP and 3 wt.‰ GO‐ZnO@EP were increased by 6.0%, 103.8% and 38.6%, 115.3%, respectively. Furthermore, compared with 1 wt.‰ ZnO‐GO@EP, the tensile modulus and elongation at break of 3 wt.‰ ZnO‐GO@EP and 5 wt.‰ ZnO‐GO@EP were increased by 39.7%, 98.9% and 69.9%, 127.8%, respectively. In addition, the tensile modulus and elongation at break of the 5 wt.‰ ZnO‐GO@EP film decreased by only 5.4% and 6.1%, respectively, compared with those before immersion in 3.5 wt.% NaCl solution, attributed to the fact that ZnO‐GO filled the internal pores of the resin, prolonging the corrosion path and hindering the entry of corrosive media such as H ₂ O, O ₂ , Cl ⁻ into the interior. It was worth noting that compared with pure EP coated‐steel, the corrosion current density of 3 wt.‰ GO@EP and 3 wt.‰ ZnO‐GO@EP coated‐steel was significantly reduced, with corresponding corrosion potentials increased by 8.5% and 24.7%, respectively.