ABSTRACT

In this research, two nanocomposites were studied as potential biocides for contemporary and historical buildings. These treatments are based on silver and titanium dioxide nanoparticles synthesized by a bottom-up method with sodium borohydride as reduction agent.

The treatments were tested on limestone from Novelda quarry (Alicante). This construction material was employed during the restoration of the Town hall of Seville (Spain). The inhibition of the biofouling growth on limestone was demonstrated previously by our research group, but their long-term effectiveness depends on the in-depth penetration of the nanocomposites. Because of that, the characterization of the penetration depth of the deposited nanocomposites in the limestones was carried out by Laser-Induced Breakdown Spectroscopy (LIBS) depth-profiling. LIBS showed successful results due to its high sensitivity to detect and locate the nanoparticles despite the small amount of nanoparticle treatment. Moreover, LIBS could be applied in situ without sampling for restoration control.