Performance evaluation of zinc oxide nanomaterial coated titanium grade–5 alloy for superior biomedical applications

Introduction This study investigates the comprehensive performance of ZnO nanoparticles coated Titanium grade–5 (Ti-6AI-4V) alloy, across diverse domains, including wear resistance, corrosion protection, cytotoxicity, and antimicrobial efficacy. Methods The ZnO nanoparticles were synthesised using a wet-chemical precipitation method and comprehensively characterized using various techniques including UV-Visible spectroscopy, X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy Disperse X-ray (EDX) analysis, and element mapping for investigating the structural, morphological and compositional properties. The ZnO nanoparticles were meticulously deposited on the titanium grade–5 alloy surface using spin coating technique, and the resulting coated alloy was characterized through SEM, EDX and element mapping to verify the compositional details and uniformity of coating on the surface. Wear resistance was evaluated using ball-ondisc tribometer method at various speeds, revealing the impact of the ZnO nanoparticles coating on mitigating surface abrasion. Results and Discussion It was observed that ZnO nanoparticles coated titanium grade–5 substrate shows minimum value of wear which is 114.22 μm at 200 rpm under a 30 N load. Potentiodynamic polarization was employed to assess the corrosion resistance, highlighting the protective role of the ZnO nanoparticles coating against corrosive environments. The results show that ZnO nanoparticles coated substrate is more resistant to corrosion compared to the uncoated substrate. Cytotoxicity was investigated through MTT (3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide) assay using mouse embryonic fibroblast cell line (NIH-3T3), shedding light on the biocompatibility of the coated titanium grade–5 alloy. The results showed 22.1% increase in cell viability of coated substrate compared to the uncoated substrate. ZnO-coated sample shows a 13.6% reduction in corrosion current (Icorr), a 5.3% increase in polarization resistance (Rp), and a 43 mV shift of the observed corrosion potential (Ecorr) toward more noble (less negative) values, all of which are internally consistent indicators of improved corrosion resistance. Additionally, antimicrobial properties were examined against the indicator strains Escherichia coli ( E.coli , MTCC-16521) and Staphylococcus aureus ( S.aureus , MTCC-3160), elucidating the potential of ZnO nanoparticles coated titanium grade–5 alloy to inhibit bacterial growth.