An inorganic route to decorate graphene oxide with nanosilica and investigate its effect on anti‐corrosion property of waterborne epoxy

Abstract

This paper reported an inorganic route that uses potassium silicate, which is one type of alkali silicate as an inorganic modifier, taking advantage of its instability and water condensation to decorate graphene oxide (GO) with nano‐SiO2. The ingredients of prepared nanocomposites were characterized by Fourier‐transform infrared spectroscopy (FT‐IR) and X‐ray photoelectron spectroscopy (XPS), and the thermodynamic property was tested by thermal gravimetric analysis (TGA). Scanning electron microscopy (SEM) was used to observe the morphology of SiO2‐GO nanocomposites. All the analyses above revealed the nano‐SiO2 (<100 nm) was deposited on the surface of GO by chemical bonds. In the meantime, the dispersion test illustrated that nano‐SiO2 played an important role in improving the dispersity of GO. The effect of SiO2‐GO nanocomposites on barrier and corrosion protection performance of SiO2‐GO nanocomposites was tested by immersion experiment and electrochemical impedance spectroscopy (EIS). The results indicated that GO was helped to block the corrosion of aggressive medium; moreover, SiO2‐GO nanocomposites had the best anticorrosion performance and the slowest rate of corrosion because of its good dispersity with waterborne epoxy coatings.