New water-based hybrid materials for the protection against water and consolidation of stone monuments.

This research aims to develop a multifunctional, water-based product for protecting and consolidating stone materials. A new synthesis strategy using water-diluted silane formulations, composed of TEOS and an alkyl monomeric silane (ETES) or a polymeric siloxane (PDMS), homogenized by ultrasonic irradiation was followed to produce hybrid networks and overcome the limitations of current hydrophobic consolidants. These formulations gave rise to low dry residues and hydrophobic surfaces on various stones, including on low and high porosity stone varieties. Despite some formulations originated cracked films, optimal concentrations of ETES and PDMS showed high protection levels against capillary water absorption with minimal impacts on the color and water vapor permeability of the stones. Besides demonstrating the initial efficacy of these new hybrid materials in modifying the inherent hydrophilic and water-absorbing properties of stones, this work further confirmed their ability to penetrate within the stone pores and their initial efficacy in consolidating porous stones. Thus, new water-based multifunctional hybrid materials capable of consolidating and protecting various types of stones from water-related damage have been developed. These novel materials align with both technical and environmental requirements. • New hybrid sonogels were prepared successfully with water-based formulations of silanes. • Different concentrations of ETES and PDMS turn various stones hydrophobic. • Optimal concentrations also reduce drastically the water absorption of very porous stones. • Formulations preserve the original water vapor permeability while offering protection. • A multifunctional role was confirmed, as they also improve the cohesion of porous stones. [ABSTRACT FROM AUTHOR]