Tailored cerium phosphate/silica hybrid epoxy for enhanced corrosion protective coating†

Abstract

The current study focuses on finding a viable and sustainable alternative to hazardous chrome-based pigments commonly used in organic anticorrosive coatings. We investigated the effectiveness of cerium and phosphate precursor modified conventional silica through a simple synthetic route. The synthesised pigment was further surface-modified with aminopropyl trimethoxy silane to improve its interaction with the epoxy binder. The resulting silane functionalised hybrid pigment-reinforced epoxy coating has a resistance of 9.91 × 10⁹ Ω cm², two and five orders of magnitude higher than those of silica–epoxy and bare epoxy coatings, respectively. Also, it shows a hydrophobic contact angle of 100°, which further enhances the barrier properties. Continuous electrochemical impedance spectroscopy (EIS) was used to examine coating performance with and without artificial defects. The results showed improved performance compared to commercial chrome-based pigments and an active protection mechanism. Our study presents a reliable, inexpensive, and healable approach using conventional silica particles to prevent steel corrosion in saline media.