Multi-functional monodispersed SiO2–TiO2 core-shell nanostructure and TEOS in the consolidation of archaeological lime mortars surfaces

• Published in: Journal of Building Engineering 2023-11, Vol.79, p.107809, Article 107809
• Main Authors: Fahmy, Abdelrhman, Gołąbiewska, Anna, Wojnicz, Wiktoria, Stanisławska, Alicja, Kowalski, Jakub, Łuczak, Justyna, Zaleska-Medynska, Adriana, Domínguez-Bella, Salvador, Martínez-López, Javier, Molina-Piernas, Eduardo
• Format: Article
• Language: English
• Subjects: Consolidation; Durability; Hydrophobic; Lime mortar; Nano-test; Photocatalytic; Self-cleaning; SiO2–TiO2 core-shell nanostructure; TEOS
• ISSN: 2352-7102; 2352-7102
• DOI: 10.1016/j.jobe.2023.107809

Archaeological traditional lime mortars are susceptible to many environmental conditions such as the impact of water (rain, humidity, groundwater, etc.), variation of temperatures' degrees, wind and/or pollution. Accordingly, this research aims to provide newly assessed multifunctional Nano-coating for the purpose of archaeological lime mortar protection. For this, the study combined physicochemical and mechanical characterizations in performance assessment of 3%, 5%, and 7% of the synthesized SiO2–TiO2 core-shell nanostructure and TEOS as consolidants on the surfaces of the experimental lime mortars. A series of techniques and tests were fulfilled for the evaluation. For analysis, X-ray diffraction and UV–Vis along with scanning electron microscopy were used to identify microstructure. Furthermore, wettability, colorimetric, self-cleaning, petrophysical, Nano-indentation, and uniaxial compressive strength tests were performed to select the most durable consolidant between 3%, 5%, and 7% SiO2–TiO2/TEOS. Durability assessments were carried out through salt weathering, thermal and UV aging tests. The results showed that 3% and 5% of SiO2–TiO2/TEOS enhanced the physical and mechanical properties of the lime mortars. On the other hand, 7% SiO2–TiO2/TEOS proved their insufficient efficacy in improving the surfaces of lime mortars for the high amount of TiO2 and its behavior for aggregation. [Display omitted] •3% and 5% SiO2–TiO2 core-shell nanostructure/TEOS enhanced the lime mortar surfaces multifunctionally.•3% and 5% are suitable consolidates for lime mortar surfaces without leaving chromatic changes.•7% SiO2–TiO2 core-shell nanostructure/TEOS did not enhance the lime mortars physically and mechanically.•Low concentration and monolayer are efficient application method for SiO2–TiO2 core-shell nanostructure/TEOS utilization.