Long-term corrosion resistance of zinc-rich paint using functionalised multi-layer graphene-tripolyphosphate: in situ creation of zinc phosphate as corrosion inhibitor

This study investigates the effect of hybrid multilayer graphene-tripolyphosphate on long-term corrosion protection efficiency of zinc-rich paint. The hybrid nanomaterial as a corrosion resistance modifier was prepared trough a simple method by the addition of sodium tripolyphosphate aqueous solution to a dispersed multi-layer graphene in water/ethanol during stirring. The performance of the hybrid nanomaterial was studied by salt spray, electrochemical impedance spectroscopy, scanning electron microscopy, X-ray diffraction, cathodic delamination and pull-off adhesion test. The experimental results showed that in the presence of 1 wt-% of the hybrid nanomaterial, cathodic protection duration increased from 28 days to more than 50 days. The improvement in the barrier property and the cathodic delamination resistance was significant in the presence of the nanomaterial after two years long-term study. X-ray diffraction analysis showed that the formation of zinc phosphate was responsible for the higher corrosion protection efficiency.