The present work was carried out within a research project dealing with conservation methods for gilded bronzes, based both on preventive actions (microclimate control) and on active methods (protective coatings). The results presented here are dealing with fire-gilded bronze samples (replicating the composition and microstructure of the materials used in Lorenzo Ghiberti’s Paradise Door (Baptistery of Florence, 1452)), which were aged in runoff conditions by accelerated exposure tests in synthetic acid rain. Both unprotected and organosilane-coated gilded bronzes were investigated, so as to assess the protective efficiency of 3-mercapto-propyl-trimethoxy-silane (select-ed on the basis of previous work) on these substrates. A detailed characterization of fire-gilded bronze samples was carried out by FIB/FEG-SEM both before and after accelerated ageing. Surface analysis and cross-sections analysis of the samples were performed also by SEM/EDS and micro-Raman spectroscopy. The protective efficiency of the organosilane coating was quantitatively assessed by the measure-ment of metal release in the ageing solution by GF-AAS.
Atmospheric corrosion of fire-gilded bronze: accelerated ageing in runoff conditions
BALBO, Andrea;MONTICELLI, Cecilia
2014
Abstract
The present work was carried out within a research project dealing with conservation methods for gilded bronzes, based both on preventive actions (microclimate control) and on active methods (protective coatings). The results presented here are dealing with fire-gilded bronze samples (replicating the composition and microstructure of the materials used in Lorenzo Ghiberti’s Paradise Door (Baptistery of Florence, 1452)), which were aged in runoff conditions by accelerated exposure tests in synthetic acid rain. Both unprotected and organosilane-coated gilded bronzes were investigated, so as to assess the protective efficiency of 3-mercapto-propyl-trimethoxy-silane (select-ed on the basis of previous work) on these substrates. A detailed characterization of fire-gilded bronze samples was carried out by FIB/FEG-SEM both before and after accelerated ageing. Surface analysis and cross-sections analysis of the samples were performed also by SEM/EDS and micro-Raman spectroscopy. The protective efficiency of the organosilane coating was quantitatively assessed by the measure-ment of metal release in the ageing solution by GF-AAS.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
