Antibacterial effect of PEO coating with silver on AA7075

- Silver particles were incorporated into PEO coatings produced on aluminum alloys.
- The incorporation was performed with direct addition of the particles in the electrolyte.
- The particles resulted equally distributed on the samples surfaces.
- The obtained coatings show antimicrobial activity with both E. coli and S. aureus.
- The obtained coatings were characterized by acceptable corrosion resistance.

In this work, plasma electrolytic oxidation (PEO) coatings were produced on AA7075 using alkaline solution containing silicates compounds and silver micrometric particles in order to give to the coating an antimicrobial effect. In the optic of circular economy, silver chloride derived from the acid pre-treatment of electronic scraps was used as raw material and successively silver powders were synthesized from silver chloride solution using glucose syrup as reducing agent.The coatings were characterized by scanning electron microscope (SEM), X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), potentiodynamic polarization test and antimicrobial tests. The results evidenced that the obtained coatings were homogenous and give to the samples higher corrosion resistance than untreated alloy. The silver particles, found both inside and outside of the pores that characterize the PEO layer, produced an efficacious antimicrobial effect both against E. coli and S. aureus.