Corrosion of an active antibacterial nanostructured coating on titanium

Abstract

This study aims on antibacterial and corrosion characterization of a complex ceramic coating based on titania (TiO2) nanotubes, hydroxyapatite (HA) and single walled carbon nanotubes (SWCNTs), in physiological environment. Hybrid materials structure was identified by Fourier transformed infrared spectroscopy (FTIR) and their surface analysed by scanning electron microscopy (SEM) and contact angle analysis. The most hydrophilic sample was the one with TiO2-HA coating. The electrochemical behavior of materials has been investigated in Ringer solution performing potentiodiynamic polarization and electrochemical impedance spectroscopy. Antibacterial properties of coatings were determined by contact method using two types of strains, one of them Staphylococus aureus (S. aureus) is a positive gram bacteria and another one Pseudomonas aureoginosa (P. aureoginosa) a negative gram bacteria. The corrosion rates are in the perfect stable domain of corrosion resistance and no breakdown phenomena were observed. A range of stability in tested bioliquid has been established from electrochemical and ICP-MS measurements. TiO2-HA-SWCNTs coating has the best corrosion resistance and the best barrier properties for ions release. Antibacterial effect of TiO2-HA-SWCNTs coating seems to be synergistic being higher compared to TiO2 nanotubes and TiO2-HA coating.