Development of hybrid epoxy nanocomposites with ZnO nanoparticles and micro TiO₂ pigmented coatings for marine like environments

Industrial infrastructures often encounter durability issues with protective coatings, which can be potentially attributed to imbalance of nanoscale impermeability and uncontrolled opacity in coating formulations. This study aims to improve the protective performance of epoxy/polyamide coatings by strategically utilizing epoxy-functional silane (3-glycidoxypropyltrimethoxysilane, GLYMO) modified zinc oxide (ZnO) nanoparticles and micro titanium dioxide (TiO₂) pigments. The formulations of these hybrid coatings are prepared by the combination of ZnO nanoparticles (1–3 wt. %) with commercial TiO₂ pigment within an epoxy matrix. An ultrasonic process is utilized to ensure homogeneous nanoparticle dispersion, followed by micron-sized TiO₂. The coating is then applied to steel substrates by means of an automatic applicator, followed by curing at ambient temperature. The optimal nanoparticle level of 2.0wt.% ZnO in the formulation demonstrated performance enhancement. The enhancement was not only seen in mechanical properties, the anticorrosion properties analyzed in 3.5% NaCl solution also showed improvement in the when compared to the coating without nanoparticles up to 21 days of exposure which confirms the successful integration of nano and micro filler. The combination of nano and micro particles creates a microstructure that successfully elevates the mechanical as well as barrier properties. Such a hybrid coating formulation can be considered as a good option for protective coatings equivalent to marine environment that requires good corrosion resistance.