Microstructural effect on the antimicrobial efficacy of arc ion plated TiO2

Photocatalytic titanium dioxide coatings prepared via various processes have been developed for antimicrobial purposes. Among them is arc ion plating, which may provide more advantages than other processes such as high growth rate, strong film adhesion, as well as the ability to obtain anatase phase at a low deposition temperature. This research involves an arc ion plating method to produce TiO2 film on stainless steel. Antimicrobial efficacy is examined as a function of coating parameters. The experimental results show that the deposited film mainly consists of a rutile phase at an initial growth stage, followed by the growth of an anatase phase at a later stage. By increasing oxygen partial pressure, an increased volume of anatase phase is obtained. The volume of anatase phase is found to strongly and positively affect antimicrobial efficiency. Such an arc ion plated TiO2 coating can be potentially served for antimicrobial treatment of medical equipment.