Anticorrosion performance of PDA and WS2 synergistically modified graphene oxide/epoxy resin composite coatings

The epoxy resin is one of the most distinguished anticorrosive organic polymers with outstanding features of excellent resistance to moisture, remarkable resistance to solvents, and great adhesion properties to various surfaces of metals. However, epoxy resin suffers from several drawbacks such as high brightness. Here, we proposed synergistic modification of GO by dopamine and tungsten disulfide (PW-GO) to improve the aggregation of GO in epoxy resin and thus enhance the anticorrosive performance of PW-GO-EP composite coatings. The 3D multilayer structure of PW-GO nanofillers effectively blocks the diffusion of corrosive media, thus providing excellent corrosion resistance. At the optimum ratio of WS2:DA:GO = 1:1:1, a minimum current density and maximum impedance were obtained. The impedance of composite coatings remained as 1.19 x 108 Omega cm2 after immersing in 3.5 wt-% NaCl aqueous solution for 45 days, indicating its excellent anticorrosive performance. The underlying mechanism is revealed in terms of the blocking effect of the 3D multilayered PW-GO nanofillers on corrosive mediums. The findings reported here will have important implications for developing new types of epoxy-based coatings.