Antibacterial titania-based photocatalytic extruded plastic films

Abstract

Abstract Photocatalytic antibacterial low density polyethylene (LDPE)–TiO 2 films are produced by an extrusion method and tested for photocatalytic oxidation activity, via the degradation of methylene blue (MB) and photocatalytic antibacterial activity, via the destruction of Escherichia coli . The MB test showed that extruded LDPE films with a TiO 2 loading 30 wt.% were of optimum activity with no obvious decrease in film strength, although the activity was less than that exhibited by the commercial self-cleaning glass, Activ ® . UVC pre-treatment (9.4 mW cm −2 ) of the latter film improved its activity, with the level of surface sites available for MB adsorption increasing linearly with UVC dose. Although the MB test revealed an optimum exposure time of ca. 60 min photocatalytic oxidation activity, only 30 min was used in the photocatalytic antibacterial tests in order to combine minimal reduction in film integrity with maximum film photocatalytic activity. The photocatalytic antibacterial activity of the latter film was over 10 times that of a non-UVC treated 30 wt.% TiO 2 film, which, in turn was over 100 times more active than Activ ® .