Abstract
The photocatalytic processes are being studied and incorporated into building systems aiming at the improvement of the quality of water and air. However, there are doubts about the impact of the action of photocatalysis on substrates and especially about how long it continues occurring and about their intensity. The proposed method consists in using a surface post treatment associated with a photocatalytic process, in order to obtain the simultaneous actions of the hydrophilic and hydrophobic effect. This paper proposes to assess the durability of photocatalytic processes by means of an experimental program, where the bodies of the mortar tests for external coating after being post-processed and stained with methylene blue solution (C16H18N3SCl) at a concentration of 1% in deionized water, and 92.8 ° in ethyl alcohol (C2H6O) were subjected to 200 cycles of artificial aging (wetting, exposure to ultraviolet and infrared radiation). The results lead to: 1) increasing the titanium dioxide concentration of methylene blue accelerates the degradation process; 2) surface treatment with aqueous dispersions of TiO2 showed a decline in performance over the tests; 3) the hydrophobic silicone-based showed a good potential as semiconductor fixing agent.
Keywords:
Photocatalysis; Durability; Aging; Mortars; Rendering
