Investigating the effect of SiO2-graphene oxide hybrid as inorganic nanofiller on corrosion protection properties of epoxy coatings

In this research, tetraethyl orthosilicate (TEOS) is used as organosilane to decorate the surface of graphene oxide (GO) nanosheets by SiO2 nanospheres via a facile method. Results of X-ray diffraction analysis, Raman spectroscopy, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, and atomic force microscopy reveal that SiO2 nanospheres have covered the surface of GO sheets through covalent bonding and SiO2-GO nanohybrids are successfully synthesized. Further, the effect of incorporating 0.1 wt GO nanosheets and/or SiO2-GO nanohybrids on properties of epoxy coatings is investigated. The results show that the pull-off adhesion strength of epoxy coatings to mild steel substrates and the water contact angle on coatings significantly increase via adding SiO2-GO nanohybrids. The potentiodynamic polarization test, electrochemical impedance spectroscopy (EIS) and salt spray test results demonstrate that corrosion protection performance of epoxy coatings remarkably enhances by embedding well-distributed SiO2-GO nanohybrids compared to GO nanosheets. (C) 2017 Elsevier B.V. All rights reserved.