Does argon anoxia cause a color change in Prussian blue pigment?

ABSTRACT

The study focused on the effect of anoxic treatment on the discoloration of Prussian blue-dyed textiles and paper. Prussian blue pigment has been known to change color in the presence of light and heat in a vacuum for quite some time, but some claims were made that a low-oxygen environment alone contributed to its fading. The aim of this study was to determine whether argon anoxic treatment would induce the same changes when kept in the dark or in the light. The results clearly show that fading of Prussian blue in an argon anoxic condition occurs in the light but not in the dark.

RÉSUMÉ

Cette étude porte sur l’effet d’un traitement par anoxie sur la décoloration des textiles et des papiers teints au bleu de Prusse. Il est connu, depuis assez longtemps, que le bleu de Prusse change de couleur en présence de la lumière et de la chaleur lorsqu’il est sous vide. Mais on a aussi rapporté qu’un environnement privé d’oxygène pouvait à lui seul faire pâlir la couleur. Le but de cette étude visait à déterminer si un traitement par anoxie à l’argon induirait les mêmes changements de couleur lorsque le bleu de Prusse est conservé dans l’obscurité ou à la lumière. Les résultats montrent clairement que dans des conditions d’anoxie à l’argon le pâlissement du bleu de Prusse se produit à la lumière, mais non dans l’obscurité. Traduit par Elisabeth Forest.

RESUMO

O estudo teve por foco o efeito do tratamento com gás na descoloração de tecido têxtil e papel tingidos por azul da prússia. O azul da prússia é conhecido por mudar de cor no vácuo, na presença da luz e do calor, por um tempo prolongado, mas algumas reclamações foram feitas que um ambiente com baixo oxigênio, apenas, contribuiu para o seu desbotamento. O objetivo deste estudo foi determinar se o tratamento com anóxia de argônio induziria às mesmas alterações quando no escuro ou na luz. Os resultados claramente mostram que o desbotamento do azul da prússia, em condições de anóxia de argônio, ocorre na luz, mas não no escuro. Traduzido por Valeria Gauz.

RESUMEN

El estudio realizado se centró sobre la decoloración de textiles y papel teñidos con azul de Prusia durante tratamientos con anoxia. Es sabido que el pigmento azul de Prusia cambia de color en presencia de luz y calor en el vacío, sin embargo hubo un planteamiento sugiriendo que un ambiente con bajo contenido de oxígeno contribuye a su decoloración. El objetivo de este estudio fue determinar si un tratamiento anóxico con argon podía inducir los mismos cambios tanto si se realizaba en la oscuridad o en presencia de luz. Los resultados muestran claramente que la decoloración del azul de Prusia durante tratamientos anóxicos con argon sólo ocurre en la presencia de luz, no si se realiza en la oscuridad. Traducido po A. Elena Charola.

KEYWORDS:

• Argon
• anoxia
• Prussian blue
• fading
• light
• substrate influence

Acknowledgments

The authors would like to thank former interns Jennifer Hau, Christine Regan, and Stephanie Spence for their work in preparing the samples and documenting the procedure used.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Daniel Koestler is a visiting researcher at the Smithsonian’s Museum Conservation Institute and a software engineer for Adobe Systems. He has previously worked with the argon-anoxia treatment method for cultural property at MCI as an intern, and recently had the opportunity to return and finish an investigation of the effects of argon treatment on Prussian blue. His work at Adobe principally concerns architecting Big Data analytics solutions for Adobe’s digital marketing platform. Address: 4204 Dandridge Terrace, Alexandria, VA 22309. USA. E-mail: [email protected]

Mary Ballard, Senior Textiles Conservator at the Smithsonian’s Museum Conservation Institute, helped organize multiple sessions with the late Dr. Helmut Schweppe on dyeing and dye analysis of natural and early synthetic dyes, and studied mordants and silk weighting with Dr Robert Koestler. She is a Fellow member of the American Institute of Conservation. Address: Museum Conservation Institute, Smithsonian Institution. 4210 Silver Hill Road, Suitland, MD 20746-2863. USA. E-mail: [email protected].

A. Elena Charola obtained her doctorate in Chemistry from the Universidad Nacional de La Plata, in her native country Argentina. After having served at the Metropolitan Museum of Art, New York City (1981–1985) and at ICCROM, Rome (1986–1987), she has been in private practice, working mainly for World Monuments Fund and its Portuguese affiliate. At the Smithsonian’s Museum Conservation Institute in Suitland, MD, she was a Visiting Scientist (2008–2010) and is currently a Research Scientist since 2011. Address: as above. E-mail: [email protected]

Robert J. Koestler earned a doctorate in biology (cell biology and electron microscopy) from the City University of New York in 1985. He has worked for more than 40 years in the heritage science field, first at the American Museum of Natural History and then at the Metropolitan Museum of Art. Since August 2004, he has been the director of the Smithsonian’s Museum Conservation Institute. He has published more than 100 papers and edited several volumes in heritage science, and has consulted on many projects worldwide for foundations, museums, collections, and government conservation institutes. He is a Professional Associate member of the American Institute of Conservation. Address: as above. E-mail: [email protected].

ORCID

Mary Ballard http://orcid.org/0000-0002-1032-2930

A. Elena Charola http://orcid.org/0000-0002-1198-7571

Robert J. Koestler http://orcid.org/0000-0001-5433-4899

Notes

1 Degrees Baumé (Bé) measure the density of a solution, using a Baumé hydrometer which is introduced into the solution and will partly submerge according to the solutiońs density.