GROSSI, DANIELLELAZAR, DOLORES R.R.DEL LAMA, ELIANE A.USSUI, VALTER2023-05-182023-05-182023GROSSI, DANIELLE; LAZAR, DOLORES R.R.; DEL LAMA, ELIANE A.; USSUI, VALTER. Titania-silica composite with photocatalytic properties and its application on Brazilian granite and sandstone. <b>International Journal of Architectural Heritage</b>, v. 17, n. 5, p. 770-787, 2023. DOI: <a href="https://dx.doi.org/10.1080/15583058.2021.1969483">10.1080/15583058.2021.1969483</a>. Disponível em: http://repositorio.ipen.br/handle/123456789/34054.1558-3058http://repositorio.ipen.br/handle/123456789/34054The aim of the study described in this article was to evaluate a product containing titania (titanium dioxide, TiO2) applied on stones — particularly two types used at Brazilian stone-built heritage sites — that have been exposed to weathering and anthropogenic activities. This product was prepared by producing a suspension of TiO2 at two concentrations (1% and 4% w/v) with tetraethyl orthosilicate (TEOS) in the presence of n-octylamine as surfactant. The characteristics of the TiO2 were then observed by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface-area measurements, particle-size distribution analysis (CILAS) and X-ray diffraction. After applying the TiO2-TEOS composite, the stones were examined for contact angle, spectrophotometry, sorptivity, thermal shock resistance, and UV-radiation resistance. The product proved ineffective on Itararé sandstone, mainly due to its mineralogical components, as the product does not adhere to quartz. When applied on Itaquera granite, the 1% TiO2 (w/v) concentration proved to be an appropriate treatment, as it demonstrated better thermal shock resistance, photocatalytic activity, porosity maintenance, and global colour when compared to the 4% concentration.770-787openAccessarchitecturecultural resourcesphotocatalysissandstonescomposite materialstitanium oxidesArtigo de periódico51710.1080/15583058.2021.19694830000-0001-7384-304Xhttps://orcid.org/0000-0001-7384-304X59.998.00