Application of a polymer-based photocatalytic coating for the protection of limestone stones substrates: an exposure study

In the last decades there have been several studies on cultural heritage regarding the performance of protective and consolidating coatings for the prevention of decay. A coating must have several characteristics such as: efficiency, breathability, and must be durable and reversible. In this research work we tried to verify the performance of a commercial protective product such as Fosbuild FBLE 200, which is composed of a TiO2 nanopowder dispersed in an aqueous solution of an acrylic polymer. This product, which exhibits depolluting, antimicrobial, water-repellent and self-cleaning characteristics, has been applied on different lithotypes such as: Carrara marble, Noto and Comiso stone and exhibited in two different outdoor environments such as Catania and Palermo. These two cities are mostly affected by pollution produced by vehicular traffic; moreover, Catania is also affected by pollution produced by the activity of Mount Etna.