FILM DI SILICE SOL-GEL PER LA PROTEZIONE DELLA CERAMICA NELL’ARCHITETTURA DI GIO PONTI A MILANO

Claudia Bortolussi1-2, Michele Cecchin1, Daniela Lattanzi3, Mari Mapelli3, Fabiola Mischiatti1, Elena Munerato1, Marta Righetti1, Renzo Bertoncello2

1 SILTEA srl, via della Croce Rossa 112, 35129 Padova, info@siltea.eu

2 Dipartimento di Scienze Chimiche, Università degli Studi di Padova, via Marzolo 1, 35131 Padova, renzo.bertoncello@unipd.it

3 MiBAC- Direzione regionale per i beni culturali e paesaggistici della Lombardia, Corso Magenta 24, 20123 Milano, daniela.lattanzi@beniculturali.it

ABSTRACT 

The church of Santa Maria Annunciata in Milan was built between 1964 and 1967 by Gio Ponti. The restoration project highlighted a complex situation connected to contemporary art. The processes of surface alteration show phenomena that cannot be found in historical buildings. Particular attention was devoted to the external ceramic facing, made of glazed porcelain stoneware tiles. The critical conservation status of the ceramic elements required an intervention for the consolidation of diffuse micro-cracking in the glassy coating and the protection of the still intact material. Silica thin films synthesized by sol-gel process, according to the technology developed at the University of Padova, was used to perform an innovative protective treatment. The method involves a new synthetic path to obtain highly pure glassy silica thin films operating at low temperatures and in neutral pH, avoiding degradation of objects sensitive to acid environment and heat treatment. Phenomena involved in weathering, as well as chemical and morphological characteristics of the ceramic materials, were analyzed in order to plan the intervention. Compatibility with the substrate, stability to UV radiation, chemical corrosion and biological degradation resistance, inalterability of the optical characteristics are all features in accordance with the restoration needs. The encouraging results show that this technology can be widely used as an alternative to traditional methods based on organic polymers.

Key-words: Sol-gel, Gio Ponti, glazed ceramics, silica coating.