Smart hybrid coatings for natural stones conservation

The protection of stone monuments against deterioration has recently attracted much attention from scientists. An accurate analysis of the degradation mechanisms of stones has led to the conclusion about the necessity of protection especially against the condensed water and the salts formation. In this study, the strengthening effect of nanoparticles-based treatments is compared to that exhibited by a silane commercial polymer. The surface properties of these types of smart coatings were investigated by different analytical techniques such as contact angle measurements and scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS). Aimed at evaluating the coating performance, exposure tests both to UV ageing and to environmental atmospheric pollution were carried out. Diffuse reflectance spectroscopy (DRS) was employed for the CIELab colorimetric coordinates assessment; while ion chromatography (IC) was adopted to evaluate the coating capacity to avoid salts (Cl-, NO3 - and SO4 2-) formation.