A comparative evaluation of bottom-up and break-down methodologies for the synthesis of calcium hydroxide nanoparticles for the consolidation of architectural monuments

This paper studies the morphological characteristics of calcium hydroxide produced following the main bottom-up (CaCl2/NaOH replacement reaction) and break-down methodologies, aiming to optimize the synthetic process of Ca(OH)2 nanoparticles, for the consolidation of natural stone monuments. Triton-X 100, n-octylamine and a nano-bubbles enriched aqueous solvent were used for the modification of the surface tension between dispersant and nano-particles. The morphological, chemical and the mineralogical characterization of the nanoparticles produced were conducted by SEM and XRD. The formation of Ca(OH)2 hexagonical nanoparticles was favored by the incorporation of oxygen nanobubbles, providing a great potential for the development of water-based stable nano-dispersions.