Synthesis and characterization of SiO2-TiO2 nanoparticles and their effect on the strength of self-cleaning cement composites

• Published in: Construction & building materials 2021-05, Vol.283, p.122769, Article 122769
• Main Authors: Shchelokova, E.A., Tyukavkina, V.V., Tsyryatyeva, A.V., Kasikov, A.G.
• Format: Article
• Language: English
• Subjects: Cement; Compressive strength; Nanomaterial; Photocatalytic activity; Self-cleaning properties
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2021.122769

•SiO2-TiO2 nanoparticles were prepared via heterocoagulation method.•The properties of SiO2-TiO2 depend on the calcination temperature at the final stage.•SiO2-TiO2 enhances the mechanical characteristics and activated the self-cleaning properties of cement paste.•The use of SiO2-TiO2 with a specific surface of more than 300 m2·g−1 allows reducing the amount of additive. SiO2-TiO2 mixed oxides have been used in this research to improve compressive strength and self-cleaning characteristics of cement. SiO2-TiO2 samples have been synthetized by the heterocoagulation method and characterized by a series of techniques, such as infrared spectra with Fourier transform, X-ray diffraction and thermogravimetric/derivative thermo-gravimetric analyses. Photocatalytic characteristics of the prepared specimens have been evaluated in methylene blue aqueous solution under ultraviolet ray irradiation. It has been found that the structural-adsorption, surface properties, and the photocatalytic activity of the SiO2-TiO2 depend on the final stage calcination temperature. The experimental results have shown that the material which was heated to 800 °C exhibited a high-specific surface area (307.1 m2·g−1) and highest photocatalytic activity. The physico-mechanical characteristics of the specimens were tested using a compressive strength study, thermogravimetric/differential thermal analysis (TG/DTA) and scanning electron microscopy (SEM) to investigate characteristics of cement pastes containing SiO2-TiO2 and without them. It has been determined that the use of SiO2-TiO2 having a specific surface area of more than 300 m2·g−1 allows reducing the amount of additive in the production of cement paste with improved technical characteristics. Results achieved have shown the optimum amount of SiO2-TiO2 in the cement paste composition to be 0.1–0.5%. Besides, the discoloration test has been used to estimate the photocatalytic activity on the treated cement surface.