Anticorrosive and Antibacterial Evaluation of ZnO Nanoscale Sheets Electrosynthesized onto Ti6Al4V and Nitinol Alloys Previously Modified by Chemical Oxidation in H2O2

Abstract

Titanium and its alloys have a crucial function in the biomaterial field. Nonetheless, susceptibility to infections is an important drawback that needs to be considered. In this context, current research on antibacterial materials for implants is a promising solution, and antibacterial coatings have considerable potential for medical applications. Within this work, the effect of ZnO nanoscale sheets (NS) electrosynthesized onto Ti6Al4V and Nitinol (NiTi) alloys was studied. These samples were previously chemically oxidized in hydrogen peroxide (H2O2) solution to improve their corrosion resistance. The anticorrosive effectiveness of ZnO NS was tested through different electrochemical techniques (open circuit potential (OCP), Tafel polarization, linear sweep voltammetry (LSV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS)), performed in Ringer solution at body temperature. The surface morphology and elemental composition was determined employing scanning electron microscopy (SEM) and energy dispersive X-ray (EDS), while X-ray photoelectron spectroscopy (XPS) was used to study the surface chemistry and composition. The presence of ZnO decreases the corrosion current density in Ringer solution contrasting with the untreated Ti alloys. The antibacterial activity of the treated surfaces was evaluated using three bacterial colonies: S. Aureus, S. Mutans and E. Coli. The ZnO NS grown on Ti6Al4V and NiTi alloys produce the inhibition of S. Aureus and S. Mutans. The findings indicate that the combination of chemical oxidation and electrochemically grown nanostructures produce a hydrophobic surface that reduces the bacteria adhesion.