Protection of marbles against corrosion and microbial corrosion with TiO₂coatings

Abstract

Abstract In the present paper the preliminary results of a study of the protective properties of TiO2 coatings, in the dark as well as under illumination, against corrosion and microbial corrosion of marbles used as construction materials in new buildings are reported. All experiments were carried out using marble specimens bare or coated with either Paraloid or two types of TiO2 coatings. From the results it follows that at the beginning the sulfation rate of Paraloid coated marbles was lower than the one of bare specimens. After some time though, cracks appeared on the coating and sulfation was accelerated, thus making its rate higher than that of un‐coated marbles. In the case of TiO2 coatings cracks were not observed and the rate of sulfation was lower compared to that of bare marbles, with the coating of maximum thickness (0.7 mm) exhibiting the best protective properties. Additionally, the antibacterial activity of TiO2 has been tested by using three representative cultures of bacteria and fungi. The results showed that in the presence of the illuminated semiconductor a complete inactivation of all kinds of microorganisms was achieved. The high reactivity and non‐selectivity of the photogenerated reactive species were responsible for this behavior.

Keywords

Affiliated Institutions

• Aristotle University of Thessaloniki GR

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