Cerium-doped tannic acid-reduced graphene oxide nanoplatform/epoxy nanocomposite coatings with enhanced mechanical and Bi-functional corrosion protection properties

Abstract

There has been an explosion of interest toward incorporating graphene-based nanomaterials for corrosion protective coatings. In this study, tannic acid (TA) was employed as a green reducing agent of graphene oxide (TA-rGO) to provide promising nanoplatforms with good dispersion in an epoxy matrix for enhanced mechanical and anti-corrosion properties. In addition, these nanoplatforms were doped with cerium cations (Ce@TA-rGO) to improve active corrosion protection. The designed nanosheets were characterized by several techniques, including FT-IR, XRD, UV–visible, FE-SEM/EDS, TEM, TGA, and XPS. TA improved the thermal properties of graphene oxide significantly with only 40% weight loss up to 800 °C. Furthermore, EIS studies revealed that introducing Ce@TA-rGO nanoplatforms into epoxy coating led to ∼71.5% improvement in active corrosion protection in a saline solution due to the smart release of Ce3+. In addition, Ce@TA-rGO nanoplatforms presented excellent barrier properties without electrolyte diffusion after 10 weeks of immersion. In terms of mechanical properties, Ce@TA-rGO-EP and TA-rGO-EP nanocomposites showed higher cross-linking densities and tensile strengths than unfilled epoxy, originating from improvement in the level of dispersion and interaction of nanoplatforms with the polymer.