Study of degradation of CdSSe pigments employed by modern artists

The project began with the study of the painting ‘Il quarto stato’ by the Italian divisionist painter Giovanni Pellizza da Volpedo. The study of the painted materials is important to obtain information on the painting process, the material's provenance, and the production technology, or to observe and prevent the degradation process. In this project, we propose to study with XAS a corpus of seven CdS1-xSex pigments produced with historical techniques and bound with four historical and modern binders, before and after artificial aging. The aim is to employ Cd K- and L3-edges, and Se and S K-edges, to observe and quantify structural changes in the pigment-binder systems due to photochemical alterations. This information will give deeper insights into the degradation processes occurring in these materials as observed in many paintings of the XIX and XX centuries, helping to better preserve these artifacts.