Corrosion inhibition of Q235 steel by epoxy coatings containing FG@ZIF‐8

Abstract In this study, ZIF‐8 modified fluorinated graphene composite (FG@ZIF‐8) was innovatively prepared and used as a novel functional filler to improve the anticorrosion performance of epoxy coating on Q235 carbon steel. The morphology and structure of FG@ZIF‐8 composites were characterized by scanning electron microscopy (SEM), x‐ray powder diffractometer (XRD), Fourier transform infrared spectrometer (FT‐IR), and x‐ray photoelectron spectroscopy (XPS) tests. The results showed that the structure and morphology of the composites largely depended on the composition ratio of FG and ZIF‐8. The mechanical properties and corrosion resistance of FG@ZIF‐8 modified coatings were also investigated. The unique two‐dimensional sheet structure and insulation of FG in the FG@ZIF‐8 filler can not only inhibit the penetration of corrosive media but also discourage electron migration effectively on the interface of coating/matrix during the electrochemical reaction. Meanwhile, the chemical cross‐linking between the amine groups in ZIF‐8 and the epoxy group increases the degree of densification of the coatings. Besides, the 2‐methylimidazole from the dissolution of ZIF‐8 on FG@ZIF‐8 will also inhibit the corrosion reaction. These advantages endow the FG@ZIF‐8 modified epoxy coatings an excellent long‐term corrosion resistance. Our findings may inspire the development of new graphene‐based materials with superior protective properties for metallic materials.