Biocompatible Mg-P coating on surface of zinc- based biomedical material, and preparation method and use thereof

A method for preparing a biocompatible Mg—P coating on a surface of a zinc-based biomedical material, the Mg—P biocompatible coating comprises a composite conversion coating of magnesium zinc phosphate and a small amount of zinc phosphate, by adjusting kinetic and thermodynamic conditions, submicron-micron sized magnesium hydrogen phosphate particles are further deposited on the surface of the composite conversion coating, comprising the following steps:

• S1. performing a pretreatment on the surface of the zinc-based biomedical material to obtain a pretreated medical zinc alloy, wherein, the pretreatment comprises a polishing, an ultrasonic cleaning, and an ultraviolet (UV)-ozone cleaning;
• and
• S2. soaking the pretreated medical zinc alloy obtained in step S1 in an acidic magnesium salt- and phosphate-containing solution at a constant temperature of 10-80° C. for between 2.5 hours to 6 hours, and conducting chemical liquid deposition (CLD) by static soaking of the pretreated medical zinc alloy in the solution to obtain the biocompatible Mg—P coating;
• wherein the magnesium salt is selected from the group consisting of magnesium sulfate, magnesium nitrate, and magnesium phosphate;
• the phosphate is selected from the group consisting of sodium phosphate, disodium hydrogen phosphate, monosodium phosphate, potassium phosphate, dipotassium hydrogen phosphate, and monopotassium phosphate;
• the concentration of magnesium salt ranges from 0.1 to 1 mol/L, and the concentration of phosphate ranges from 0.15 to 1.5 mol/L;
• the molar ratio of magnesium salt to phosphate is between 0.5 and 5;
• the solution containing magnesium salt and phosphate also comprises a solubilizing salt, and the pH of the solution is between 4.0 and 6.2;
• in step S2 the solubilizing salt comprises ethylene diamine tetraacetic acid (EDTA).