Bactericidal Activity of Aqueous Acrylic Paint Dispersion for Wooden Substrates Based on TiO2 Nanoparticles Activated by Fluorescent Light

Abstract

The photocatalytic effect of TiO₂ has great potential for the disinfection of surfaces. Most studies reported in the literature use UV activation of TiO₂, while visible light has been used only in a few applications. In these studies, high concentrations of TiO₂, which can compromise surface properties, have been used. In this work, we have developed an acrylic-water paint dispersion containing low TiO₂ content (2 vol %) for the inactivation of microorganisms involved in hospital-acquired infections. The nanoparticles and the coating have been characterized using spectroscopic techniques and transmission electron microscopy, showing their homogenous dispersion in the acrylic urethane coating. A common fluorescent light source was used to activate the photocatalytic activity of TiO₂. The paint dispersion showed antimicrobial activity against <i>Escherichia coli</i>, <i>Staphylococcus aureus</i> and <i>Pseudomonas aeruginosa</i>. The coating containing the TiO₂ nanoparticles maintained good UV stability, strong adhesion to the substrate and high hardness. Therefore, the approach used is feasible for paint formulation aimed at disinfection of healthcare surfaces.