A hybrid consolidant of nano-hydroxyapatite and silica inspired from patinas for stone conservationA hybrid consolidant of nano-hydroxyapatite and silica inspired from patinas for stone conservation Κεφάλαιο σε Βιβλίο Book Chapter 2019-10-012018enA hybrid consolidant with high affinity to carbonaceous substrates was synthesized by adding synthesized nano-hydroxyapatite into TEOS sol, while for the first time, amylamine (CH3(CH2)4NH2) was used as a surfactant, providing an efficient means of protecting gels from cracking by reducing the capillary pressure. Amylamine is characterized by a short chain amine molecule, therefore, the amphiphilicity increased by the hydrophilic functional groups and hydrophobic tail groups without causing the formation of any amphiphilic molecule clusters. The hydroxyapatite was selected on the grounds of the weathering resistance often encountered in well-preserved monument surfaces (patinas) and attributed to the combination of hydroxyapatite, with calcium oxalate, and silica. The role of hydroxyapatite and amylamine in the silica structure was further examined by comparing the synthesized consolidant with other nanocomposites containing TEOS, TEOS and hydroxyapatite, and TEOS and amylamine as basic reagents. The synthesized products have been characterized and evaluated for their effectiveness as strengthening agents on limestone that is widely used in the historic and modern architectural structures in the Mediterranean basin. Generally, the nanocomposite-treated stone demonstrated an improvement in hygric properties, drilling resistance, and tensile strength due to the crack-free structure of the nanocomposite.http://creativecommons.org/licenses/by/4.0/Advanced Materials for the Conservation of Stone Maravelaki Pagona Μαραβελακη Παγωνα Verganelaki Anastasia Βεργανελακη Αναστασια Springer Nature [academic journals on nature.com] Consolidant Patinas Hydroxyapatite Stone Protection