Behaviour of self-cleaning glass in urban atmosphere

In order to analyse the self-cleaning mechanism of TiO₂-coated window float glass, a field experiment was conducted in Paris, at a site representative of background urban pollution. Two hydrophilic photocatalytic TiO₂-coated industrial glasses and a traditional float glass (reference) were exposed in unsheltered and sheltered condition for various time duration. The sheltered exposure allowed to study the soiling and self-cleaning mechanism without the disturbing effect of rain washing. In parallel, air filtrations were carried out in order to assess the chemical composition of airborne particulate.