Ascertaining the degradation state of ceramic tiles : a preliminary non-destruc...

• Author(s): Silva, Teresa Pereira ; Figueiredo, M. Ondina ; Prudêncio, Maria Isabel
• Date: 2013
• Persistent ID: http://hdl.handle.net/10400.9/2107
• Origin: Repositório do LNEG
• Subject(s): Património cultural; Degradação; Patologias; Cerâmica; Azulejo; Fluorescência de raios-X; Espectrometria de raios X
• Document Type: Article
• Language: English

Description

Conserving the cultural heritage is a general concern and the use of non-destructive techniques to characterize ancient materials is important. Serious deterioration effects in environmentally exposed ancient glazed ceramic tiles arise from the development of micro-organisms (algae/fungi) within the pore system. Subsequent biodegradation processes are particularly harmful once the decorated glaze is damaged by exfoliation/detachment. Three case studies will be addressed: Portuguese polychrome decorated tiles from the interior of two churches (16th–17th century) and from the outdoor of a Palace (18th century). Small tile fragments were directly irradiated in a wavelength-dispersive X-ray fluorescence spectrometer for glaze chemical characterization and subsequently irradiated in a powder diffractometer to assess the phase constitution of both glaze and ceramic body. Cleaning and conserving these ancient cultural artifacts involve a decontamination process applying innovative non-destructive techniques. The present work is intended as a contribution to diagnose the actual degradation state of ancient tiles in view of future decontamination actions using gamma radiation.