Flexible, disposable photocatalytic plastic films for the destruction of viruses

• Published in: Journal of photochemistry and photobiology. B, Biology Biology, 2022-10, Vol.235, p.112551-112551, Article 112551
• Main Authors: Han, Ri, Coey, Jonathon D., O'Rourke, Christopher, Bamford, Connor G.G., Mills, Andrew
• Format: Article
• Language: English
• Subjects: Antiviral agents; antiviral properties; Cardiovirus A; Catalysis; Cool white light; COVID-19; Curtains; Deactivation; Extrusion; fluorescence; Fluorescent lamps; health services; Humans; Inactivation; Influenza A; Influenza A virus; Irradiance; Irradiation; light intensity; Low density polyethylenes; photobiology; Photocatalysis; plastic film; Plastics; Polyethylene; Polymer films; SARS; SARS-CoV-2; Severe acute respiratory syndrome coronavirus 2; Titanium; Titanium dioxide; Tubes; Ultraviolet radiation; Ultraviolet Rays; Viral diseases; Viruses
• ISSN: 1011-1344; 1873-2682
• DOI: 10.1016/j.jphotobiol.2022.112551

A thin, 30 μm, flexible, robust low-density polyethylene, LDPE, film, loaded with 30 wt% P25 TiO2, is extruded and subsequently rendered highly active photocatalytically by exposing it to UVA (352 nm, 1.5 mW cm−2) for 144 h. The film was tested for anti-viral activity using four different viruses, namely, two strains of Influenza A Virus (IAV), WSN, and a recombinant PR8, encephalomyocarditis virus (EMCV), and SARS-CoV-2 (SARS2). The film was irradiated with either UVA radiation (352 nm, 1.5 mW cm−2; although only 0.25 mW cm−2 for SARS2) or with light from a cool white fluorescent lamp (UVA irradiance: 365 nm, 0.047 mW cm−2). In all cases the films exhibited an average virus inactivation rate of >1.5log/h. In the case of SARS2, the rates were > 2log/h, with the rate determined using a dedicated, low intensity UVA source (0.25 mW cm−2) only 1.3 x's faster than that for a cool white lamp (UVA irradiance = 0.047 mW cm−2), which suggests that SARS2 is particularly prone to photocatalytic inactivation even under low UV irradiation conditions, such as found in a room lit with just white fluorescent tubes. This is the first example of a flexible, very thin, photocatalytic plastic film, produced by a scalable process (extrusion), for virus inactivation. The potential of such a film for use as a disposable, self-sterilising thin plastic material alternative to the common, non-photocatalytic, inert equivalent used currently for curtains, aprons and table coverings in healthcare is discussed briefly. [Display omitted] •Production of a flexible, thin, photocatalytic plastic film by extrusion.•Film activated using UVA.•Tested using two influenza viruses, encephalomyocarditis virus, and SARS-CoV-2 (SARS2).•All measured average virus inactivation rates >1.5log/h with UVA and cool white light.•SARS2 particularly prone to photocatalytic inactivation even under very low UV irradiation conditions.