Enhanced Corrosion Protection of Epoxy Coatings by Exfoliated and Hydrophobically Modified Kaolinite: Synergistic Effects of Barrier Properties and Hydrophobic Surface Treatment

In this study, we aimed to enhance the corrosion resistance of epoxy coatings by incorporating hydrophobically modified exfoliated kaolinite as a lamellar filler.The effects of LiCl concentration and treatment temperature during the exfoliation process were thoroughly investigated.Surface activation and modification were confirmed using FT-IR and XPS analysis.Contact angle measurements showed improved wettability of epoxy coat with the addition of kaolinite.Electrochemical impedance spectroscopy (EIS) analysis demonstrated the superior corrosion resistance of epoxy coatings with 10 wt.% of hydrophobically modified kaolinite, maintaining coating resistance values of 10⁸-10⁹ Ω•cm² after 670 h immersion in 3.5 wt.% NaCl solution, two orders of magnitude higher than pristine epoxy (5.8×10⁴ Ω•cm²).Contact angle increased from 65° to 76°, indicating enhanced hydrophobicity.Our study presents novel findings on the potential of barrier effects and hydrophobicity in corrosion prevention, offering a cost-effective method.