Assessment of protection treatments for carbonatic stone using nanocomposite coatings

In this paper the effect of the application of four kinds of polymer dispersions containing nanoparticles, used as protectives, on two type of carbonatic lithotypes, White Noto and Comiso stone, is reported. The study was conducted by analysing the contribution of each component of the system. After the structural characterization of the coating itself, the performance of those colloidal systems has been studied upon application on the calcarenites, preferring non-invasive techniques and microdestructive techniques. Effect of the nanoparticles presence on hydrorepellency and roughness of the stone surface and on chromatic changes has also been considered. The tests conducted have proven that although some of the formulations present some issues for their usage on White Noto stone, all four formulations induce an effective waterproofing action on Comiso stones, even in presence of TiO2 and SiO2 nanoparticles.