title: Field-emission scanning electron microscopy and energy-dispersive x-ray analysis to understand the role of tannin-based dyes in the degradation of historical wool textiles.
abstract: An innovative approach, combining field-emission scanning electron microscopy (FESEM) with energy dispersive X-ray spectroscopy (EDX) analysis, is presented to investigate the degradation mechanisms affecting tannin-dyed wool. In fact, tannin-dyed textiles are more sensitive to degradation then those dyed with other dyestuffs, even in the same conservation conditions. FESEM-EDX was first used to study a set of 48 wool specimens (artificially aged) dyed with several raw materials and mordants, and prepared according to historical dyeing recipes. EDX analysis was performed on the surface of wool threads and on their cross-sections. In addition, in order to validate the model formulated by the analysis of reference materials, several samples collected from historical and archaeological textiles were subjected to FESEM-EDX analysis. FESEM-EDX investigations enabled us to reveal the correlation between elemental composition and morphological changes. In addition, aging processes were clarified by studying changes in the elemental composition of wool from the protective cuticle to the fiber core in cross-sections. Morphological and elemental analysis of wool specimens and of archaeological and historical textiles showed that the presence of tannins increases wool damage, primarily by causing a sulfur decrease and fiber oxidation.
authors.affiliation: 1Dipartimento di Chimica e Chimica Industriale,Università di Pisa,via Risorgimento 35,56126 Pisa,Italy.
authors.forename: Annalaura
authors.initials: A
authors.lastname: Restivo
authors.affiliation: 1Dipartimento di Chimica e Chimica Industriale,Università di Pisa,via Risorgimento 35,56126 Pisa,Italy.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Degano
authors.affiliation: 1Dipartimento di Chimica e Chimica Industriale,Università di Pisa,via Risorgimento 35,56126 Pisa,Italy.
authors.forename: Erika
authors.initials: E
authors.lastname: Ribechini
authors.affiliation: 2Instituto Universitario de investigación en Ciencias Ambientales de Aragón (IUCA),Universidad de Zaragoza,Pedro Cerbuna 12,50009 Zaragoza,Spain.
authors.forename: Josefina
authors.initials: J
authors.lastname: Pérez-Arantegui
authors.affiliation: 1Dipartimento di Chimica e Chimica Industriale,Università di Pisa,via Risorgimento 35,56126 Pisa,Italy.
authors.forename: Maria Perla
authors.initials: MP
authors.lastname: Colombini
mesh_terms: D000818:Animals; D004396:Coloring Agents / Q000032:analysis*; D008855:Microscopy, Electron, Scanning / Q000379:methods*; D013052:Spectrometry, X-Ray Emission / Q000379:methods*; D013634:Tannins / Q000032:analysis*; D013784:Textiles; D014935:Wool / Q000737:chemistry* / Q000648:ultrastructure*
chemical_list: D004396:Coloring Agents; D013634:Tannins