Construction of a PEO/Mg-Mn LDH composite coating on Mg-Ag-Mn alloy for enhanced corrosion resistance and antibacterial potential

Endowing magnesium alloys with both durable antibacterial ability and reliable corrosion resistance is an urgent task for the development of magnesium-based implants. In this work, Mg-Mn layered double hydroxide (LDH) intercalated with organic salicylic acid (SA) anion was synthesized on a PEO-coated Mg-Ag-Mn alloy via the combination of co-precipitation and hydrothermal treatments. The PEO layer endows Mg-Ag-Mn alloy with a moderate corrosion barrier and the Mg-Mn LDH layer not only seals the PEO defects, but also acts as a reservoir for antibacterial agents (namely SA). The PEO/Mg-Mn LDH composite coating on Mg-Ag-Mn alloy dramatically increases its corrosion resistance by up to 3 orders of magnitudes, which also tailors the ionic release kinetics for a desired antibacterial potential to prevent bacterial infection.