TY - JOUR
T1 - The multi-analytical in situ analysis of cadmium-based pigments in plastics
AU - Angelin, Eva Mariasole
AU - Ghirardello, Marta
AU - Babo, Sara
AU - Picollo, Marcello
AU - Chelazzi, Laura
AU - Melo, Maria João
AU - Nevin, Austin
AU - Valentini, Gianluca
AU - Comelli, Daniela
N1 - Funding Information:
info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/UID%2FQUI%2F50006%2F2019/PT#
This research was funded by Funda??o para a Ci?ncia e Tecnologia, Minist?rio da Educa??o e da Ci?ncia (FCT/MCTES), Portugal, through doctoral programme CORES-PD/00253/2012; PhD grants PB/BD/114412/2016 (Eva Mariasole Angelin), SFRH/BD/52318/2013 (Sara Babo);
This research was also partially funded by the Erasmus+ for Traineeship program 2018/2019 (participant: Marta Ghirardello).
PY - 2020/9
Y1 - 2020/9
N2 - Colorants are present in trace concentration in objects made of plastic and their identification is a methodological and analytical challenge. In conservation, the identification of colorants may allow a better understanding of colorant degradation (such as color change and fading) and provide information about the historical development, production and processing of plastics. Although micro-destructive analytical protocols are well established for the analysis of colorants, in cultural heritage, where in situ methodologies are preferred and, in some cases, mandatory, new approaches are greatly needed. In this work, an in situ multi-analytical approach is used to specifically study inorganic cadmium-based pigments that were commonly used for coloring plastics during the 20th c. First introduced as vivid artists’ pigments, cadmium-based additives were used for coloring plastics because of their exceptional performance properties. Eighteen colored polymethyl methacrylate (PMMA) samples, produced in the second half of the 20th c. by the company Plásticos do Sado (Portugal), were studied with a combination of optical microscopy, colorimetry, UV–Vis-NIR diffuse reflectance, laser-induced photoluminescence, vibrational (µ-Raman) and elemental (µ-EDXRF) spectroscopies. On the basis of complementary data, the chemical composition of most of the coloring agents employed in the acrylic samples were identified without any micro-sampling.
AB - Colorants are present in trace concentration in objects made of plastic and their identification is a methodological and analytical challenge. In conservation, the identification of colorants may allow a better understanding of colorant degradation (such as color change and fading) and provide information about the historical development, production and processing of plastics. Although micro-destructive analytical protocols are well established for the analysis of colorants, in cultural heritage, where in situ methodologies are preferred and, in some cases, mandatory, new approaches are greatly needed. In this work, an in situ multi-analytical approach is used to specifically study inorganic cadmium-based pigments that were commonly used for coloring plastics during the 20th c. First introduced as vivid artists’ pigments, cadmium-based additives were used for coloring plastics because of their exceptional performance properties. Eighteen colored polymethyl methacrylate (PMMA) samples, produced in the second half of the 20th c. by the company Plásticos do Sado (Portugal), were studied with a combination of optical microscopy, colorimetry, UV–Vis-NIR diffuse reflectance, laser-induced photoluminescence, vibrational (µ-Raman) and elemental (µ-EDXRF) spectroscopies. On the basis of complementary data, the chemical composition of most of the coloring agents employed in the acrylic samples were identified without any micro-sampling.
KW - Cadmium pigments
KW - Cultural heritage
KW - Laser-induced photoluminescence
KW - Plastic artefacts
KW - Raman microscopy
KW - UV–Vis-NIR diffuse reflectance spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=85085750401&partnerID=8YFLogxK
U2 - 10.1016/j.microc.2020.105004
DO - 10.1016/j.microc.2020.105004
M3 - Article
AN - SCOPUS:85085750401
SN - 0026-265X
VL - 157
JO - Microchemical Journal
JF - Microchemical Journal
M1 - 105004
ER -