Modified triazine decorated with Fe3O4 and Ag/Ag2O nanoparticles for self-healing of steel epoxy coatings in seawater

New hybrid nanomaterials based on Fe3O4 and Ag/Ag2O nanoparticles (NPs) supported by 2,4-dihydrazino-6-(methoxypolyethyleneglycol)-1,3,5-triazine (mPEGTH) were successfully synthesized without using reducing agents in both solution and solid phases. The mechanism for Fe3O4 and Ag/Ag2O NPs formation in the presence of mPEGTH, their chemical structures, surface morphologies, crystal structures, thermal stabilities and mPEGTH contents were characterized and identified. The effects of seawater salinity and pH of solutions on the Fe3O4 and Ag/Ag2O NPs surface charges and particle sizes distributions were examined to investigate their performances under aggressive conditions. It was found that, the Fe3O4/mPEGTH, hybrid nanomaterials obtained good dispersed NPs and exhibit a remarkable superiority in enhancing the anticorrosion performance of epoxy coatings more than Ag/Ag2O NPs. The Fe3O4/mPEGTH nanomaterials achieved significant synergistic effect to improve the anticorrosion and self-healing performances for epoxy composite coatings. They achieved higher salt spray resistance up to 1500 h without rust formation. The new self-healing mechanism of Fe3O4/mPEGTH nanomaterials was tentatively discussed.