TEOS modified with nano-calcium oxalate and PDMS to protect concrete based cultural heritage buildingsTEOS modified with nano-calcium oxalate and PDMS to protect concrete based cultural heritage buildings Peer-Reviewed Journal Publication Δημοσίευση σε Περιοδικό με Κριτές 2021-09-172020enThis work has been supported by the InnovaConcrete project funded by the European program Horizon 2020 (GA no. 760858).Cultural Heritage constructions of twentieth century consist largely of mortar and concrete substrates. These concrete structures have suffered different types of decay processes. One of the most widely used consolidants is the Tetraethoxysilane (TEOS), which forms the basis of most existing commercial strengthening agents to protect porous building materials against deterioration. A novel, non-toxic strengthening and protective agent for mortar and concrete substrates was synthesized in a one-pot sol-gel procedure, incorporating in TEOS, Polydimethyl siloxane (PDMS), and nanoparticles of synthesized calcium oxalate (CaOx). PDMS provided hydrophobicity and reduced surface tension that causes cracks on the surface of produced xerogel. The synthesized nanocomposite both in sol and xerogel form was assessed with a variety of analytical techniques (FTIR, XRF, SEM, Optical Microscopy, Dynamic Light Scattering, Thermogravimetric analysis). The excellent physical properties of the produced colloidal solution of the nanocomposite, such as low viscosity and density, allow a penetration up to 2 cm from the surface in the treated cement mortars. This involved improvement of the mechanical and physical properties, such as the dynamic modulus of elasticity and increased water repellency. The treated cement mortars exhibited well-preserved aesthetic surface parameters and significant maintenance of the treatment. Furthermore, no harmful byproducts were identified indicating the nanocomposite compatibility to the siliceous and carbonate nature of the treated cement mortars.http://creativecommons.org/licenses/by/4.0/Frontiers in Materials7Kapetanaki_et_al_Front. Mater._7_2020.pdfChania [Greece]Library of TUC2021-09-16application/pdf2.2 MBfree Kapetanaki Kali Καπετανακη Καλη Vazgiouraki Eleftheria Βαζγιουρακη Ελευθερια Stefanakis Dimitrios Στεφανακης Δημητριος Fotiou Afroditi Φωτιου Αφροδιτη Anyfantis George C. García-Lodeiro Ines Blanco Varela, María Teresa Arabatzis Ioannis Maravelaki Pagona Μαραβελακη Παγωνα Frontiers Media PDMS-TEOS-nano-calcium oxalate nanocomposite Concrete conservation Hydrophobic consolidant Compatible Cultural heritage conservation