Abstract

Titanium dioxide based nanocomposites for stone coating have been found to be promising in laboratory conditions to obtain manifold protective actions against pollution and weathering affecting the outdoor built heritage. Lasting performances in real conditions of these multifunctional coatings have been scarcely examined, although this is a key issue in evaluating their potential for applications in a real building context and their optimization. This paper illustrates a field study aimed at investigating simultaneous hydrophobic and self-cleaning effectiveness, on the medium-long run, of TiO2 NPs/fluoropolymer coatings applied on a limestone. The samples coated with the nanocomposites were exposed for one year in an urban environment and their surface was monitored. Hydrophobic properties were checked through contact angle measurements and a capillary water absorption test, while self-cleaning efficiency was evaluated by a photodegradation test of Rhodamine B. Optical microscopy observations and colour measurements were also performed. In addition, the contents of Ti and water-soluble ions on the sample surfaces were determined by X-ray Fluorescence and ion chromatography, respectively. The overall findings showed that TiO2 NPs did not affect the ability of the polymer to protect the stone surface against water penetration. The coatings were able to preserve the surfaces from dirt. However, photocatalytic efficiency progressively decreased, due to the loss of the photocatalyst from the coating surface, which may be attributed to a polymer modification by ageing. The embedding of nanosized titania within the polymer limited the adsorption and accumulation of soluble salt ions on the coated surface, which may increase the stone damage risk.

Autore Pugliese

• Calia Angela , Masieri Maurizio

Tutti gli autori

• Colangiuli D.; Lettieri M.; Masieri M.; Calia A.

Titolo volume/Rivista

Science of the total environment

Anno di pubblicazione

2019

ISSN

0048-9697

ISBN

Non Disponibile

Numero di citazioni Wos

Nessuna citazione

Ultimo Aggiornamento Citazioni

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Numero di citazioni Scopus

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Ultimo Aggiornamento Citazioni

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Settori ERC

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Codici ASJC

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