Large-scale preparation of fluorographene/epoxy nanocomposite coatings on steel for corrosion protection

Graphene, due to its unique two-dimensional structure and superior barrier property, is considered as an excellent filler in organic coatings used for the corrosion protection of metals. However, it has also been found to promote the metal corrosion because of its high electrical conductivity. In this work, we used electrically insulated fluorographene (FG) nanoplatelets as fillers for epoxy coatings and investigated their corrosion protection properties for metals. FG was prepared by a microwave-assisted liquid phase exfoliation method and then was incorporated into epoxy matrix through an environment-friendly solventless method. The electrochemical impedance spectroscopy (EIS) and the potentiodynamic polarization measurements show that the prepared FG/epoxy nanocomposite coatings exhibit superior anticorrosion performance, which are improved by one order of magnitude compared with the pure epoxy coating. The improvement of the corrosion resistance of the nanocomposite coatings is mainly attributed to the barrier properties and electrical insulation of FG nanoplatelets. Moreover, the nanocomposite coating containing 0.5 wt% FG shows the best anticorrosion performance because of the uniform dispersion of a small amount of FG nanoplatelets in the epoxy matrix.