TRATTAMENTI INNOVATIVI A BASE DI ESTERI SILICICI PER IL CONSOLIDAMENTO DI MANUFATTI A BASE SILICATICA

G. Botticelli*, M. Matteini**, S. Lugli***, S. Minghelli****, P. Zannini****

*     Restauratore, Libero Professionista

**     Istituto per la Conservazione e la Valorizzazione dei Beni Culturali del CNR

***   Università di Modena e Reggio Emilia, Dipartimento di Scienze della Terra

****Università di Modena e Reggio Emilia, Dipartimento di Chimica, Via Campi 183, 41125 Modena paolo.zannini@unimore.it   

ABSTRACT:

This study is intended to increase the knowledge about the evaluation of the Ethyl Silicates  effects, if used as consolidant on sandstones and silicate surfaces in Cultural Heritage materials.

Sandstones provided by the classic quarries of  Firenzuola (FI) were first studied.

Then, artificial test pieces based on powdered Fiorenzuola’s stone were realized to have test samples better simulating the level of degradation and decohesion of historical sandstones. On these samples many different treatments have been tested, with the aim to improve the mechanical properties of the treated samples.

Eight commercial products, based on Ethyl Silicate, were studied preliminary by different analytical techniques (FTIR, NMR, ICP-MS, HPLC), then, they were applied through different techniques to the artificial samples. The levels of impregnation and distribution obtained and the possible chemical interaction was checked by SEM-EDS, FTIR, XRF, XRD and other techniques.

The characterization of the treated samples was made by the sponge contact method (Normal test) and two mechanic resistance tests to superficial and depth abrasion (by ISO methods). 

Some positive result obtained encouraged to continue with further research in which the consolidating action of the ethyl silicate products will be combined and integrated with other treatments, in order to improve the quality and effectiveness of the consolidating process (work in progress).

Key-words: conservation, sandstone, Ethyl Silicate, consolidation, artificial samples.