RT Journal Article
T1 SO2-induced aging of hematite- and cinnabar-based tempera paint mock-ups: influence of binder type/pigment size and composition
A1 Pozo Antonio, José Santiago
A1 Jiménez Desmond, Daniel José
A1 De Villalobos, Lara
A1 Mato, Ana
A1 Dionísio, Amélia
A1 Rivas Brea, Maria Teresa
A1 Cardell, Carolina
K1 3312.08 Propiedades de Los Materiales
K1 3303.13 Tecnología de la Conservación
K1 6203.07 Pintura
K1 3308 Ingeniería y Tecnología del Medio Ambiente
AB Hematite- and cinnabar-based paint mock-ups prepared with either rabbit glue or egg yolk binder were artificially aged in an SO2-rich atmosphere, as a model system for investigating the deterioration of tempera paints exposed to an industrial atmosphere. The overall research aim was to identify the type of degradation occurring in tempera paints and the different alteration mechanisms related to the physical, mineralogical and chemical characteristics of the paint. Tempera mock-ups were prepared by mixing binder (egg yolk or rabbit glue) and pigment (cinnabar of different particle sizes or hematite) and were then exposed to SO2 for 2 months in accelerated aging tests. The colour, gloss, reflectance, roughness and micro-texture of the surfaces of the mock-ups were determined before and after the tests. In addition, chemical and mineralogical changes were determined by X-ray Powder Diffraction (XRPD), Attenuated Total Reflection-Fourier Transform Infrared spectroscopy (ATR-FTIR) and Scanning Electron Microscopy with Energy-Dispersive X-ray Spectroscopy (SEM-EDS) analysis. Colorimetric changes were confirmed, mainly in the cinnabar-based paints containing egg yolk, and in the hematite-based paints containing rabbit glue. Neoformed mineral phases have not been detected by XRPD, but precipitation of gypsum on the exposed surfaces has been confirmed by SEM. For cinnabar-based paints, the amount of sulfate-rich deposits was higher on egg yolk mock-ups than on rabbit glue samples, though the opposite was observed for the hematite-based paints. This confirmed the influence of the binder composition and pigment-binder tandem in the susceptibility to SO2 deposition. Pigment particle size did not have a clear influence on the physical and chemical changes in the tempera mock-ups during the ageing tests.
PB Minerals
SN 2075163X
YR 2023
FD 2023-02-18
LK http://hdl.handle.net/11093/4666
UL http://hdl.handle.net/11093/4666
LA eng
NO Minerals, 13(2): 289 (2023)
NO Financiado para publicación en acceso aberto: Universidade de Vigo/CISUG
NO Xunta de Galicia | Ref. ED431F 2022/07
DS Investigo
RD 04-dic-2023