MgAl-V2O7 4- LDHs/(PEI/MXene)10 composite film for magnesium alloy corrosion protection

In this study, MgAl-V2O74- LDHs/(poly(ethyleneimine)(PEI)/MXene)n composite films were synthesized via (i) in-situ hydrothermal growth of Mg-Al layered double hydroxides (LDHs) on AZ31 alloy followed by vanadate intercalation reactions, and (ii) the as-prepared MgAl-V2O74- LDHs film was covered by layer-by-layer assembly using (PEI/MXene)n, where n=5, 10, and 20. Film characterization revealed that the outer layers (PEI/MXene) were assembled on the surface by electrostatic interaction and provided a good coverage of LDHs nanosheets. But, microcracks appeared gradually on the surface and destroyed the film integrity with increasing number of PEI/MXene layers. The corrosion tests indicated that the MgAl-V2O74- LDHs/(PEI/MXene)10 composite films provided a better corrosion protection ability than that of n=5 and 20. The outer layers (PEI/MXene) had a corrosion inhibition protective effect on MgAl-V2O74- LDHs film. This work opened a new perspective of the MXene materials for anticorrosion application via a layer-by-layer assembly method.