Synthesis and characterization of hybrid materials based on graphene oxide and silica nanoparticles and their effect on the corrosion protection properties of epoxy resin coatings

Abstract

This study focuses on the use of tetraethyl orthosilicate (TEOS) as a silica source to decorate the surface of graphene oxide (GO) nanosheets and the use of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane (Z-6020) as a coupling agent through a one-step in-situ sol-gel process. The results of the Fourier transform infrared spectroscopy (FT-IR), UV-visible, X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA) revealed that fine SiO2 nanoparticles have successfully been synthesized on the basal plane of GO by covalent bonding. The dispersion of GO sheets and GO–SiO2 nanohybrids within the epoxy matrix was studied using XRD and SEM techniques. Then, the effect of incorporating 0.1 wt% GO sheets and GO–SiO2 nanohybrids on the corrosion protection and barrier performance of the epoxy coating was also investigated. The results showed that the incorporation of GO–SiO2 into the epoxy matrix improved its thermal stability. The electrochemical impedance spectroscopy (EIS) test, potentiodynamic polarization and cathodic disbonding test showed that the corrosion protection performance was significantly enhanced by the incorporation of GO–SiO2 hybrids into the epoxy resin compared to epoxy/GO and neat epoxy resin, respectively. The water contact angle (CA) results confirmed the reduction of the hydrophobic nature of the surface after the incorporation of GO–SiO2 hybrids.