ANTIBACTERIAL PROPERTIES OF A PHOTOCATALYTIC PAINT-LIKE COATING FOR THE PROTECTION OF BUILDING MATERIALS AGAINST MICROBIAL PROLIFERATION

摘要

Building materials can be the target of microbial proliferation in various types of environments, either indoor or outdoor. The consequences are serious and may impact both the health of building occupants, through degradation of the indoor air quality, and the structural integrity of building materials. As photocatalysis is effective against a wide range of pollutants and since paint-like coatings are surface treatments that are easy to implement, TiO_2 paint-like coatings seem to offer a promising solution for preventing microbial development on building materials. This paper focuses on the evaluation of the photo-induced hydrophilicity and antibacterial activity of TiO_2 coating applied to various materials. The results show contact angles near 10° for all coated materials after a first UV-irradiation. The required irradiation time seems to depend on the surface roughness of the support materials. The coating presented a significant antibacterial activity against Escherichia coli after a few hours of testing under low irradiation. Pre-irradiation of the coating was also observed to increase its antibacterial activity. A synergetic effect between photocatalysis and photo-induced hydrophilicity is assumed regarding the antibacterial properties of the coating.