Fungal Colonization of Weathered Radiata Pine Surfaces Protected with Inorganic Nanoparticles and Coatings

Photoactive nanoparticles are used to reduce microbial colonization and self-clean surfaces of materials such as glass ceramics. To test whether an approach is feasible for wood surfaces, we treated radiata pine samples with TiO2 (rutile anatase) or ZnO then coated the different finishes. Coated uncoated controls were exposed outdoors six months. After exposure, fungi colonizing identified using molecular techniques microscopy, colour changes in also measured. Treatment reduced discolouration during weathering but had little effect on by black mould fungi. In contrast, pretreatment titanium dioxide increased number diversity including basidiomycetes samples, whereas zinc oxide opposite effect. Zinc nanoparticles, however, less effective than rutile at reducing natural weathering. We conclude that none photoactive their own able discoloration samples. This suggests it may be difficult create self-cleaning nanoparticles.