AIC's 46th Annual Meeting

Ancient stone artifacts and architecture deteriorate over time due to environmental factors, air pollution, salt efflorescence, and biodeterioration. As a result, effective stone consolidants are necessary for the conservation and protection of stone materials. Alkoxysilanes are effective stone consolidants, undergoing hydrolysis and condensation to produce a sol-gel coating capable of penetrating the stones porous structure. However, demands for improvements in commercial formulations have led to research efforts focused on increasing flexibility, “breathability” and durability without compromising water repellency and strength. In order to allow water vapor evaporation out of the pores after consolidation application, a “breathable” consolidant is required to permit the transport of water molecules. Polyhedral Oligomeric Silsesquioxane (POSS) structurally contains nano-meter sized pores, allowing for permeability of water molecules out of the stone in addition to added mechanical durability. Polydimethylsiloxane (PDMS) was utilized for increasing flexibility and water repellency. Currrent research is focused on formulating POSS, PDMS, and other additives into alkoxysilane stone consolidants for limestone and marble substrates.