Improved corrosion protection of waterborne epoxy/graphene coating by combining non-covalent and covalent bonds

High-efficient anti-corrosive epoxy coating, containing homogeneously dispersive graphene (Gr), has been achieved by combining non-covalent and covalent bonds. Tannic acid (TA) has been used as intercalators to disperse Gr in water via pi - pi non-covalent bond to form Gr-TA hybrids. Consequently, gamma-(2,3-epoxypropoxy) propytrimethoxysilane was used to modify the surface of Gr-TA via covalent bond to enhance the interactions between Gr-TA and epoxy. The corrosion resistance properties of the composite Gr-TA/epoxy coatings were tested by electrochemical experiment and salt spray test. The results showed that anti-corrosion properties of Gr-TA-KH560/epoxy composite coatings were hugely enhanced compared with those of the Gr-TA/epoxy and pure epoxy.