Photoactive titania is able to activate chemical reactions in the presence of UV radiation by producing a free electron and an electron hole. These can activate e.g. decomposition of organic compounds and oxidation. This phonemena has inspired the development of new products that possess so called photoactive functional surface properties. Being a fine powder, titania needs to be bound with some kind of adhesive material. Organic binders have the disadvantage of becoming potentially decomposed in the course of the photoactive reactions, whereas inorganic binders remain intact. Cement (OPC) as the most widely used binder would be one obvious choice. White mortar samples containing titania (TiO2) were found to turn yellow during the exposure to UV-light both in outdoor and laboratory conditions. The discoloration could harm the visual appearance of high quality concrete surfaces if not taken into consideration while selecting the titania type. Key words: Photoactivity, UV exposure, titania, concrete, discoloration.
|Journal||Nordic Concrete Research|
|Publication status||Published - 2011|
|MoE publication type||A1 Journal article-refereed|
|Event||XXI Nordic Concrete Research Symposium - Hotel Rantasipi Aulanko, Hämeenlinna, Finland|
Duration: 30 May 2011 → 1 Jun 2011
- functional surface