Fly ash-based zeolite/reduced graphene oxide/polymer anti-corrosion coatings for efficient heat dissipation

Industries are demanding more and more for the high corrosion protection and thermal conductivity of organic coatings. However, organic coatings always have low thermal conductivity, and the effective distribution of inorganic particles within these organic coatings remains imperative for further enhancing both anti-corrosion and thermal conductivity capabilities simultaneously. Herein, a novel method is introduced for the exfoliation of reduced graphene oxide (rGO) through wet ball milling, incorporating fly ash-based zeolites. The resulting particles (A-rGO) formed two structures: rGO sheets wrapped around or partially loaded on the surface of zeolite particles. Notably, the absolute zeta potential of A-rGO measures 47.8, marking a 4.26-fold increase compared to rGO, thereby facilitating enhanced dispersion within the coating matrix. Then, benzoxazine/A-rGO based coatings are made, which formed a thermally conductive pathway and constructed an anti-corrosion barrier. The results showed that the highest thermal conductivity of the prepared coating (A-r-2) was as high as 1.561 W·m⁻¹ K⁻¹, which was 676.1 % higher than that of benzoxazine based coating, and 159.7 % higher than that of the same content of benzoxazine/rGO coating. Furthermore, the low-frequency impedance value of the A-r-2 coating reached 2.433 × 10⁹ Ω·cm² with a water contact angle as high as 129.8 ± 0.2°. The particles designed in this study provides a new system additive for fabricating highly thermally conductive composite coatings with high corrosion resistance.