Abstract

ABSTRACT The 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.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.