The article focuses on evaluating the applicability of protective coatings, specifically titanium dioxide (TiO2), on glazed wall tiles to prevent biological colonisation and biodeterioration. The study involved applying thin films of TiO2 obtained by sol-gel on various Portuguese glazed tiles and a modern tile. Chemical and mineralogical characterization of the tiles was conducted using spectroscopy and X-ray diffraction. The TiO2 coating was further analysed for its anti-biofouling properties through microscopy techniques.
Results indicated that the TiO2 coatings, while immobilising nanoparticles on the surface, did not effectively prevent fungal growth on the tiles. The study highlighted challenges in developing coatings for glazed tiles, emphasising the need to consider substrate properties like roughness and porosity. The coatings showed minimal impact on reducing tile bioreceptivity, with fungal proliferation observed on both treated and non-treated samples.
Digital image analysis was used to quantify the percentage of tile surface colonised by the fungus Cladosporium sp., revealing higher fungal proliferation on non-treated samples compared to TiO2-treated ones. However, an exception was noted where treated tiles exhibited increased fungal growth. Additionally, the study evaluated the chromatic alteration caused by the thin-film deposition, indicating aesthetic changes due to the coating application.
In conclusion, the research demonstrated the limitations of TiO2 coatings in preventing biological colonisation on glazed tiles, suggesting the need for further exploration of alternative protective measures for cultural heritage applications. The study contributes valuable insights into the challenges and considerations involved in developing effective coatings for preserving glazed wall tiles against biodeterioration.
