Creating anti-viral high-touch surfaces using photocatalytic transparent films

Abstract

Antimicrobial and self-cleaning surface coatings are promising tools to combat the growing global threat of infectious diseases and related healthcare-associated infections (HAIs). Although many engineered TiO₂-based coating technologies are reporting antibacterial performance, the antiviral performance of these coatings has not been explored. Furthermore, previous studies have underscored the importance of the "transparency" of the coating for surfaces such as the touch screens of medical devices. Hence, in this study, we fabricated a variety of nanoscale TiO₂-based transparent thin films (anatase TiO₂, anatase/rutile mixed phase TiO₂, silver-anatase TiO₂ composite, and carbon nanotube-anatase TiO₂ composite) via dipping and airbrush spray coating technologies and evaluated their antiviral performance (Bacteriophage MS2 as the model) under dark and illuminated conditions. The thin films showed high surface coverage (ranging from 40 to 85%), low surface roughness (maximum average roughness 70 nm), super-hydrophilicity (water contact angle 6-38.4°), and high transparency (70-80% transmittance under visible light). Antiviral performance of the coatings revealed that silver-anatase TiO₂ composite (nAg/nTiO₂) coated samples achieved the highest antiviral efficacy (5-6 log reduction) while the other TiO₂ coated samples showed fair antiviral results (1.5-3.5 log reduction) after 90 min LED irradiation at 365 nm. Those findings indicate that TiO₂-based composite coatings are effective in creating antiviral high-touch surfaces with the potential to control infectious diseases and HAIs.

Keywords: Antimicrobial; Antiviral; Photocatalyst coatings; Self-cleaning surfaces; TiO(2) coatings; Transparent coatings.