Investigation into the Antibacterial Behavior of TiO2 Protective Coatings for Stainless Steel

Abstract

Corrosion is considered as one of the main reasons for material and energy losses. In this study while using titania nanoparticles on stainless steel to enhance its corrosion resistance properties the material was also investigated for its antibacterial properties. Pure and silver doped titania nanoparticles were prepared by liquid impregnation method and their characterization was done using XRD, EDS and SEM. SEM characterization results showed these particles to be in nano-range i.e. 78-103nm similarly EDS confirmed composition of titanium dioxide and oxygen to be 55% and 45% respectively. Corrosion testing was done according to ASTM B895 standard involving immersion testing, 1% silver doped titania sample showed 80% corrosion resistance as compared to pure and control sample. Two bacterial strains (Staphylococcus aureus gram-positive and Escherichia coli gram-negative) were used for microbial testing under different light sources. 99% and 93% bacterial disinfection under UV and visible light was observed in samples coated with 1% silver doped titania. Apart from lab scale testing practical application of these coatings was also assessed and higher bacterial disinfection efficiencies were observed with 1% silver doped titania. Overall results showed that compared to pure titania nanoparticles, silver doped titania nanoparticles showed higher corrosion resistance as well as higher bacterial disinfection efficiencies even under visible light.