Effect of a SO<sub>2</sub> Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints
In order to improve our knowledge of the weathering response of tempera paints exposed to an industrial atmosphere, azurite- and malachite-based paint mock-ups prepared with either rabbit glue or egg yolk binders were artificially aged in an SO<sub>2</sub> rich atmosphere. The aim was to...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-05-01
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| Series: | Minerals |
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| Online Access: | https://www.mdpi.com/2075-163X/10/5/424 |
| _version_ | 1797568393268690944 |
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| author | Jose Santiago Pozo-Antonio Carolina Cardell Diana Barral Amelia Dionisio Teresa Rivas |
| author_facet | Jose Santiago Pozo-Antonio Carolina Cardell Diana Barral Amelia Dionisio Teresa Rivas |
| author_sort | Jose Santiago Pozo-Antonio |
| collection | DOAJ |
| description | In order to improve our knowledge of the weathering response of tempera paints exposed to an industrial atmosphere, azurite- and malachite-based paint mock-ups prepared with either rabbit glue or egg yolk binders were artificially aged in an SO<sub>2</sub> rich atmosphere. The aim was to identify the different alteration mechanisms and forms of degradation in the paints by observing their physical (color, gloss, reflectance, and roughness), mineralogical, chemical, and micro-textural characteristics. Superficial physical changes were evaluated by stereomicroscopy, spectrophotometry, gloss measurement, hyperspectral imaging, and roughness measurements. Chemical and mineralogical changes were evaluated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy with microanalysis (SEM-EDS), which was also used to evaluate the micro-texture of the paints. The differences between the fresh temperas were due mainly to the binder (egg yolk or rabbit glue) used in the paint mixture, which also played a crucial role in the different deterioration patterns in the artificially aged paint mock-ups. Thus, the egg yolk-based paints remained physically quite intact after SO<sub>2</sub> exposure, although they suffered more significant chemical degradation, above all in the form of copious precipitation of Cu and Ca-rich sulfate salts and the subsequent yellowing of the egg yolk binder. The SO<sub>2</sub> aged rabbit glue-based mock-ups showed microscopically important crack formation and binder loss and fewer sulfated salts precipitated on the surface of the paints. |
| first_indexed | 2024-03-10T19:55:22Z |
| format | Article |
| id | doaj.art-4a47c20aeb084236a88b032bda6779f6 |
| institution | Directory Open Access Journal |
| issn | 2075-163X |
| language | English |
| last_indexed | 2024-03-10T19:55:22Z |
| publishDate | 2020-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Minerals |
| spelling | doaj.art-4a47c20aeb084236a88b032bda6779f62023-11-19T23:58:15ZengMDPI AGMinerals2075-163X2020-05-0110542410.3390/min10050424Effect of a SO<sub>2</sub> Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based PaintsJose Santiago Pozo-Antonio0Carolina Cardell1Diana Barral2Amelia Dionisio3Teresa Rivas4Departamento de Enxeñaría de Recursos Naturais e Medio Ambiente, Universidade de Enxeñaría de Minas e Enerxía, Universidade de Vigo, 36310 Vigo, SpainDepartment of Mineralogy and Petrology, Faculty of Science, University of Granada, 18071 Granada, SpainDepartamento de Enxeñaría de Recursos Naturais e Medio Ambiente, Universidade de Enxeñaría de Minas e Enerxía, Universidade de Vigo, 36310 Vigo, SpainCERENA, Instituto Superior Técnico, Universidade de Lisboa. Av. Rovisco Pais, 1049-001 Lisboa, PortugalDepartamento de Enxeñaría de Recursos Naturais e Medio Ambiente, Universidade de Enxeñaría de Minas e Enerxía, Universidade de Vigo, 36310 Vigo, SpainIn order to improve our knowledge of the weathering response of tempera paints exposed to an industrial atmosphere, azurite- and malachite-based paint mock-ups prepared with either rabbit glue or egg yolk binders were artificially aged in an SO<sub>2</sub> rich atmosphere. The aim was to identify the different alteration mechanisms and forms of degradation in the paints by observing their physical (color, gloss, reflectance, and roughness), mineralogical, chemical, and micro-textural characteristics. Superficial physical changes were evaluated by stereomicroscopy, spectrophotometry, gloss measurement, hyperspectral imaging, and roughness measurements. Chemical and mineralogical changes were evaluated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy with microanalysis (SEM-EDS), which was also used to evaluate the micro-texture of the paints. The differences between the fresh temperas were due mainly to the binder (egg yolk or rabbit glue) used in the paint mixture, which also played a crucial role in the different deterioration patterns in the artificially aged paint mock-ups. Thus, the egg yolk-based paints remained physically quite intact after SO<sub>2</sub> exposure, although they suffered more significant chemical degradation, above all in the form of copious precipitation of Cu and Ca-rich sulfate salts and the subsequent yellowing of the egg yolk binder. The SO<sub>2</sub> aged rabbit glue-based mock-ups showed microscopically important crack formation and binder loss and fewer sulfated salts precipitated on the surface of the paints.https://www.mdpi.com/2075-163X/10/5/424tempera paintazuritemalachiteartificial agingSulfur dioxidecultural heritage |
| spellingShingle | Jose Santiago Pozo-Antonio Carolina Cardell Diana Barral Amelia Dionisio Teresa Rivas Effect of a SO<sub>2</sub> Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints Minerals tempera paint azurite malachite artificial aging Sulfur dioxide cultural heritage |
| title | Effect of a SO<sub>2</sub> Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints |
| title_full | Effect of a SO<sub>2</sub> Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints |
| title_fullStr | Effect of a SO<sub>2</sub> Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints |
| title_full_unstemmed | Effect of a SO<sub>2</sub> Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints |
| title_short | Effect of a SO<sub>2</sub> Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints |
| title_sort | effect of a so sub 2 sub rich atmosphere on tempera paint mock ups part 2 accelerated aging of azurite and malachite based paints |
| topic | tempera paint azurite malachite artificial aging Sulfur dioxide cultural heritage |
| url | https://www.mdpi.com/2075-163X/10/5/424 |
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