SELF-CLEANING TITANIA COATINGS FOR BETTER PRESERVATION OF ARCHITECTURAL HERITAGE

Enrico Quagliarini1, Federica Bondioli2, Placido Munafò1, Giovanni Battista Goffredo1, Luca Riderelli3

1 DICEA Department of Architecture, Building and Civil Engineering, Polytechnic University of Marche, via Brecce Bianche, 60131, Ancona, Italy, e.quagliarini@univpm.it

2 DIMA Department of Materials and Environmental Engineering, University of Modena and Reggio Emilia, via Vignolese 905, 41100, Modena, Italy, federica.bondioli@unimore.it

3 SIMAU Department of Materials, Environmental Sciences and Urban Planning, Polytechnic University of Marche, via Brecce Bianche, 60131, Ancona, Italy, l.riderelli@univpm.it

ABSTRACT

Self-cleaning treatments can be a promising tool in order to better preserve the original aspect and characteristics of stone surfaces and Architectural Heritage. In addition, the realization of easy-to-clean surfaces limits cleaning and maintenance actions, thus reducing their costs.

Titanium dioxide nano-particles can be used to obtain transparent self-cleaning coatings degrading and removing stains and polluting agents thanks to its photo-induced properties: super-hydrophilicity and photocatalicity.

Aqueous TiO2 solution was deposited in two different amounts by spray coating on travertine, a porous limestone largely used in historical and monumental building, obtaining a single-layer coating and a three-layers coating.

The present work was carried out in order to verify the effectiveness of titania sols and the absence of adverse effects on treated historical stone surfaces by appearance, wettability and self-cleaning analyses.

Obtained results were promising for future applications: the transparency of the coatings, the absence of significant changes in the morphology of limestone and the self-cleaning efficiency seem to allow the use of these coatings on historical and architectural surfaces made up by travertine.

Further analyses are currently under way in order to better evaluate durability and feasibility of use of these coatings in the field of stone conservation.

Key-words: Self-cleaning surfaces, Architectural Heritage, titanium dioxide, stone surfaces, photocatalysis