by Kotsoni, A., Lagkadinos, S., Stefanakis, D., Karapanagiotis, I. and Maravelaki, P.N.
ABSTRACT
Materials that dispose hydrophobic and super-hydrophobic properties have been increasing interest in the last decades, as they could remove water and develop consolidation properties on substrates. This strategy involves an effective process to protect building materials from damage, caused both by weathering and environmental air pollution, especially in the ongoing climate change. This research study presents the synthesis of a transparent, hydrophobic and superhydrophobic coating (under specific cases), named STP-Gns, that is implemented using the sol-gel method. Ingredients of STP-Gns include tetraethoxysilane (TEOS), completely hydrolyzed by oxalic acid, incorporating a hydrophobic molecule, the hydroxyl-terminated polydimethylsiloxane (PDMS). Hydrophobicity is enhanced in the coatings by embedding silica (SiO2) nanoparticles into the polymer solution, at an appropriate concentration. STP-Gns was applied on Alfas stones as well as Pentelic and Carrara marbles to evaluate the hydrophobic properties. Treated specimens were evaluated by FT-IR spectroscopy, SEM/TEM microscopy, Dino-lite, colorimeter and static contact angle measurement. The innovation of this synthesis lies in the application of a super-hydrophobic and consolidant nanocomposite that gives high contact angles degrees. The produced crack-free coating is non-toxic, eco-friendly, and compatible with various substrates, while requiring a simple and non-energy-intensive production process.
