Historical oil paintings undergo complex chemical transformations as they age, triggering the production of a wide variety of metal carboxylates within the paint films. Metal soaps and oxalates are two metal carboxylate types known to irreversibly modify an oil painting’s physical, chemical, and aesthetic properties, often threatening its long-term conservation. Fundamental aspects of the metal carboxylate-mediated degradation of such paintings are still poorly understood. For instance, certain ionic phenomena involving metal soaps and oxalates, suspected to alter oil paint films, have not been explored. The EEHOP project (Electromagnetic Exploration of Historical Oil Paintings) is an interdisciplinary research project that will investigate how ionic dissociation, exchange, and migration processes occurring between metal soaps and oxalates are correlated to a film’s electrical properties, chemical composition and ambient relative humidity. To do so, we will innovatively introduce a wideband electromagnetic characterization methodology in the heritage oil paint research field. We aim to determine how an oil film’s electrical complex permittivity evolves with aging and changes in chemical composition, or water content due to relative humidity fluctuations. By such an approach we hope to be able to probe the ionic exchange and migration processes between metal soaps and oxalates via the detected variation of the film’s electrical properties at various humidity rates.
Plus d’informations :
[Website Université catholique de Louvain] et [Website KIK-IRPA]