Antibacterial titania-based photocatalytic extruded plastic films

• LDPE–TiO2 films produced by extrusion.
• UVC pre-conditioning enhances the photocatalytic and antibacterial activity of the film.
• Adsorption surface site density measured using a spectrophotometric technique.
• Photocatalytic and antibacterial properties of the films are superior to Activ® self-cleaning glass.

Photocatalytic antibacterial low density polyethylene (LDPE)–TiO2 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 TiO2 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.% TiO2 film, which, in turn was over 100 times more active than Activ®.

Plastic TiO2 film is ca. 1000 times more effective against E. coli than commercial photocatalytic glass Activ®.Figure optionsDownload as PowerPoint slide