Enhanced corrosion resistance of epoxy coatings through the incorporation of modified TiO2 and reduced graphene oxide

Abstract

Anti-corrosion coatings ensure material safety and extend service life, serving as important safeguards in the fields of construction, infrastructure, petrochemicals, and marine engineering. Therefore, this study introduces a dual-nanofiller synergistic system by blending epoxy resin, 3-hydroxy-2-naphthylhydrazine modified reduced graphene oxide, and TiO2 nanofillers modified with the silane coupling agent KH570 to create a novel nanocomposite coating. Compared to traditional coatings, the synergistic effect of the dual nanofillers formed a dense nanonetwork structure, enhancing the corrosion resistance and mechanical properties of the coating. The results show that the composite coating has a smooth surface with minimal crack formation. In addition, the toughness and wear resistance of the composite coatings were improved. Electrochemical Impedance Spectroscopy analysis revealed that the impedance value of the Dual nanofiller composite coating was two orders of magnitude higher than that of the other coatings, showing the strongest corrosion resistance. A 45-d long-term immersion experiment was conducted on the composite coatings. The results showed that after 45 d of immersion in 3.5 wt% NaCl solution at room temperature, the Z modulus of the dual nanofiller composite coating decreased from 109 Ω·cm2 to 107 Ω·cm2. Although the performance declined, the coating still exhibited relatively high corrosion resistance and no significant physical defects, maintaining a good overall structure. This study provides an ideal method for enhancing the corrosion resistance of coatings by using a dual-nanofiller synergistic system.