Bactericidal and photowetting effects of titanium dioxide coatings doped with iron and copper/fluorine deposited on stainless steel substrates

Abstract

Titanium dioxide coatings, doped either with Fe or with a Cu/F combination, were deposited onto 316 LVM steel with radio frequency plasma enhanced chemical vapor deposition technique. As a source of titanium, titanium (IV) chloride was used, while iron pentacarbonyl and copper(II) (6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionate) served as precursors for iron and copper/fluorine, respectively. The coatings were evaluated in terms of their surface topography using atomic force microscopy, phase composition using low angle X-ray diffraction and chemical composition using both Raman and Furrier transform infrared spectroscopies. Mechanical properties, such as adhesion, hardness and Young modulus, were tested. Finaly, bacteriostatic and bactericidal properties of the films as well as their water wettability under ultraviolet light illumination were assessed. The coatings had primarily amorphous structure, with the exemption being those containing 0.5 and 1.4 atomic % of iron, where anatase/rutile and rutile reflexes were recorded, respectively. Mechanical properties of the films were found to be satisfactory and their bactericidity substantial.