Inorganic nanomaterials for the consolidation of wall paintings and stones

This chapter reports on the usage of inorganic nanomaterials for the compatible and stable consolidation of wall paintings and stone artefacts. As a matter of fact traditional consolidants, either inorganic (aqueous Ca(OH)2 solutions or dispersions) or organic (e.g. acrylate or vinyl acetate polymers), exhibit several limitations and drawbacks. On the other hand, dispersions of calcium hydroxide nanoparticles in short chain aliphatic alcohols ensure optimal consolidation effects, as highlighted by several case studies. Mixed formulations, including barium, strontium, magnesium and calcium hydroxides, can be used on salt contaminated plasters and other carbonate-based stones, thanks to their different chemical reactivity and to the physico-chemical characteristics of carbonates they form.