Silver deposition on polypyrrole films electrosynthesised onto Nitinol alloy. Corrosion protection and antibacterial activity

Abstract

The electrosynthesis of polypyrrole films onto Nitinol from sodium salicylate solutions of different concentrationsis reported. The morphology and corrosion protection properties of the resulting coatings were examined and they both depend on the sodium salicylate concentration. The immobilisation of silver species in PPy films constituted by hollowrectangular microtubeswas studied as a function of the polymer oxidation degree. The highest amount of silver was deposited when the coated electrode was prepolarised at −1.00 V (SCE) before silver deposition, suggesting an increase in the amount of non-oxidised segments in the polymer. Finally, the antibacterial activity of the coating against the Gram positive Staphylococcus aureus and Staphylococcus epidermidis bacteria was evaluated. Both strains resulted sensitive to the modified coatings, obtaining a slightly better result against S. aureus.