In situ deposition reduced graphene oxide-silica for improving the corrosion resistance of organic epoxy coatings: A comparative study

In this study, two facile routes for in situ construction and characterization of silica particles decorated with reduced graphene oxide (rGO-SiO 2 ) based on the sol-gel principle are reported and incorporated into epoxy resins to prepare coatings for comparative testing of their corrosion protection and mechanical properties. The microstructure, phase identification and composition of the hybrid materials were characterized by SEM, XRD, and FT-IR, respectively. The results demonstrated that both two methods can successfully generate silica on the surface of reduced graphene oxide, but the silica generated by method I had lower content and finer size. And this trend was more obvious with the increase of reaction time. The mechanical properties and anticorrosion behavior of the epoxy coatings were investigated by coating adhesion automated scratch test, contact angle, salt spray test and EIS test. The results were shown that incorporation of rGO-SiO 2 hybrids (produced in both methods I and II) into the epoxy coating notably enhanced its bongding strength, dispersion performance, barrier properties and corrosion resistance. It was also indicated that the hybrid material prepared by method I after 48h had the best mechanical and anti-corrosion properties.