Surface characterization and corrosion behavior of silanized magnesium coated with graphene for biomedical application

We here report the use of thin layers of graphene oxide (GO) as a protective coating that inhibits corrosion of underlying magnesium (Mg) metal. In order to coat the GO layer, Mg surfaces were hydroxylated with NaOH solution followed by silanization with dipping in 3-aminopropyltriethoxysilane (APTES) solution and subsequent coating with GO. Here, electrochemical methods were employed to study the corrosion behavior of Mg by coating graphene on it using multi-step coatings. Potentiodynamic polarization measurement determined that the graphene coating effectively inhibited the metal from corrosion. Electrochemical impedance spectroscopy (EIS) measurements suggested that graphene film on metal surface protect the metal from oxidation. This was as a result of impermeability of GO coatings to ions diffuse of oxidizing gas and corrosive liquid solution.