PHOTOCHEMICAL POTENTIAL OF TITANIA PAINTING AT A HIGHWAY TUNNEL PORTAL. COMPARISON WITH THE CONDITIONS MEASURED ON SITE

The aim of this study is to evaluate the photoactivity of a commercial TiO2 coating at a highway tunnel, illuminated by UV-A lamps

Photocatalytic action of water-based TiO2 paint inside a highway tunnel

European Symposium on Photocatalysis. CITE' MONDIALE BORDEAUX - FRANC

Self-cleaning titania coatings for better preservation of architectural heritage

The development and application of self-cleaning treatments on historical and architectural stone surfaces could bring a significant improvement in conservation, protection and maintenance of Cultural Heritage. The aim of this investigation is the application of titanium dioxide based coating on historical and architectural surfaces to evaluate its possible use as a self-cleaning treatment.Titanium dioxide based coating was obtained by sol-gel and hydrothermal (134 °C) processes and then the TiO2 sol was applied on travertine (a limestone largely used in historical buildings of Mediterranean area) by spray coating in two different ways, obtaining a single-layer and a three-layer coating.In order to verify the potential use of TiO2 based coating in the field of Architectural Heritage, the maintenance of appearance properties of treated surfaces was monitored by colour and gloss analyses. Static contact angle and wettability were monitored to assess possible changes in surface properties of treated stones and to evaluate photo-induced hydrophilicity. Static contact angle analysis, water adsorption, de-pollution and soiling removal tests were carried out under UV-light exposure to evaluate photo-induced effects and self-cleaning efficiency.Obtained results show that analyzed TiO2 based treatments modify the aestethic aspect of the treated surfaces in a negligible way, while without UV-light exposure there are no evident changes in static contact angle, capillary rise and wettability of treated surfaces. The trasparency of the coatings and the absence of significant changes in the morphology of the limestones seem to allow the use of these coatings on historical and architectural surfaces made up by travertine.Photo-induced effects (hydrophilicity, nitrogen oxide and soiling degradation) are very evident. Treated surfaces show hydrophilic behaviour during UV-light exposure, but this increase in wettability does not seem to lead to higher values of water adsorption, since water creates a film on solid surface without being adsorbed. The analyzed TiO2 coatings are able to effectively photo-degrade NO under UV-light exposure and to accelerate the degradation process of deposited dye. The combination of these properties may lead to an actual self-cleaning effect.The deposited amount of TiO2 through spray coating does not seem to increase photo-induced properties, since just outer layer is in contact with UV-light and external materials to be degraded, like NO (as well as other polluting substances) and deposited soiling

Self-cleaning titania coatings for better preservation of architectural heritage

The development and application of self-cleaning treatments on historical and architectural stone surfaces could bring a significant improvement in conservation, protection and maintenance of Cultural Heritage. The aim of this investigation is the application of titanium dioxide based coating on historical and architectural surfaces to evaluate its possible use as a self-cleaning treatment.Titanium dioxide based coating was obtained by sol-gel and hydrothermal (134 \ub0C) processes and then the TiO2 sol was applied on travertine (a limestone largely used in historical buildings of Mediterranean area) by spray coating in two different ways, obtaining a single-layer and a three-layer coating.In order to verify the potential use of TiO2 based coating in the field of Architectural Heritage, the maintenance of appearance properties of treated surfaces was monitored by colour and gloss analyses. Static contact angle and wettability were monitored to assess possible changes in surface properties of treated stones and to evaluate photo-induced hydrophilicity. Static contact angle analysis, water adsorption, de-pollution and soiling removal tests were carried out under UV-light exposure to evaluate photo-induced effects and self-cleaning efficiency.Obtained results show that analyzed TiO2 based treatments modify the aestethic aspect of the treated surfaces in a negligible way, while without UV-light exposure there are no evident changes in static contact angle, capillary rise and wettability of treated surfaces. The trasparency of the coatings and the absence of significant changes in the morphology of the limestones seem to allow the use of these coatings on historical and architectural surfaces made up by travertine.Photo-induced effects (hydrophilicity, nitrogen oxide and soiling degradation) are very evident. Treated surfaces show hydrophilic behaviour during UV-light exposure, but this increase in wettability does not seem to lead to higher values of water adsorption, since water creates a film on solid surface without being adsorbed. The analyzed TiO2 coatings are able to effectively photo-degrade NO under UV-light exposure and to accelerate the degradation process of deposited dye. The combination of these properties may lead to an actual self-cleaning effect.The deposited amount of TiO2 through spray coating does not seem to increase photo-induced properties, since just outer layer is in contact with UV-light and external materials to be degraded, like NO (as well as other polluting substances) and deposited soiling

Use of photocatalytic products for sustainable construction development

Sustainable development implies effort in order to be able to improve and safeguard future environmental conditions, while improving actual quality of life. A key aspect of this approach is related to construction materials and technologies sustainability since development is strictly related to construction capacity, not only for housing but even and mainly for infrastructures. Within this frame the use of photocatalytic products has been promoted and exploited, due to their ability to abate organic as well inorganic air pollutants and keep surfaces clean with time. In particular, the photocatalytic activity of paint, mortar, render and concrete made with a photocatalytic cement has been considered when applied to road infrastructures, like pervious concrete pavements, concrete lining and coatings for tunnels and also road accessories like barriers and walls

Durability of NO Oxidation Effectiveness of Pavement Surfaces Treated with Photocatalytic Titanium Dioxide

Nowadays, photocatalysis has demonstrated to be a reliable solution in order to purify the atmosphere from the pollutants originated by vehicular traffic. Owing to the primary importance of this problem, the potential of innovative photocatalytic techniques, dealing with the immobilization of titanium dioxide TiO2 on the surface of the asphalt pavement, has been investigated. In particular, three different products, two bituminous emulsions and a cement mortar, were applied on the right lane and on the emergency lane of a highway section in Italy. The effectiveness of the photocatalytic treatments and its evolution with time were evaluated on cores taken after 1, 17, 46, 88, 218, and 527 days from the application of the products. Two tests were carried out on the cores: The NO degradation was evaluated through continuous flow tests, and the size of the treated areas was quantified by means of digital image analysis methods. The research showed interesting results, as all the techniques, in particular the bituminous emulsion-based products, proved to have a good effectiveness in air de-polluting, even if a decay of performance was noted, depending of traffic and weather conditions