Photochemistry of Artists' Dyes and Pigments: Towards Better Understanding and Prevention of Colour Change in Works of Art. Issue 25 (28th May 2018)

• Record Type: Journal Article
• Authors: Miliani, Costanza; Monico, Letizia; Melo, Maria J.; Fantacci, Simona; Angelin, Eva M.; Romani, Aldo; Janssens, Koen
• Is Part Of: Angewandte Chemie international edition. Volume 57:Issue 25(2018)
• Page Start: 7324
• Page End: 7334
• Publication Date: 2018-05-28
• Subjects: art conservation -- dyes and pigments -- photochemistry -- photodegradation -- redox chemistry; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201802801
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The absorption of light gives a pigment its colour and its reason for being, but it also creates excited states, that is, new molecules with an energy excess that can be dissipated through degradation pathways. Photodegradation processes provoke long‐term, cumulative and irreversible colour changes (fading, darkening, blanching) of which the prediction and prevention are challenging tasks. Of all the environmental risks that affect heritage materials, light exposure is the only one that cannot be controlled without any impact on the optimal display of the exhibit. Light‐induced alterations are not only associated with the pigment itself but also with its interactions with support/binder and, in turn, are further complicated by the nature of the environmental conditions. In this Minireview we investigate how chemistry, encompassing multi‐scale analytical investigations of works of art, computational modelling and physical and chemical studies contributes to improve our prediction of artwork appearance before degradation and to establish effective preventive conservation strategies. Abstract : What light does to colours : Light may provoke irreversible colour changes of artworks due to chemical transformations of their constitutive materials. Chemistry, by exploiting multi‐scale analytical investigations, computational modelling and physical and chemical studies, contributes to improve our prediction of artwork appearance before degradation and to establish effective preventive conservation strategies.