Characterization of traditional artificial patinas on copper using the voltammetry of immobilized particles

The voltammetry of immobilized particles methodology (VIMP) is used to characterize the composition of artificial patinas on copper. The voltammetric response of carbonate-, nitrate-, chloride-, sulfate-, and sulfide-based patinas is described using sub-microsamples attached to graphite electrodes in contact with aqueous acetate buffer. Patina-characteristic voltammetric profiles are obtained for the different artificial patinas that can be recognized using the generalized Tafel analysis of the voltammetric curves. VIMP data could also provide layer-by-layer information about composition and compactness/crystallinity of the patinas for which a simplified theoretical modeling is presented.Authors gratefully acknowledge funding from Project CTQ2017–85317-C2–1-P, supported with Ministerio de Economía, Industria y Competitividad (MINECO), Fondo Europeo de Desarrollo Regional (ERDF) and Agencia Estatal de Investigación (AEI); and project TOP-HERITAGE CM (S2018/NMT_4372) from Comunidad de Madrid and European Structural and Investment Funds. B. R.-B. and E.C. would like to professional support of the CSIC Interdisciplinary Thematic Platform “Open Heritage: Research and Society” (PTI-PAIS)