A Comparison of Materials for Dry Surface Cleaning Soot-Coated Papers of Varying Roughness: Assessing Efficacy, Physical Surface Changes, and Residue

ABSTRACT

To provide detailed information to aid conservators faced with soot removal, a survey comparing the removal of lamp black pigment, serving as a model soot, from three sample papers of differing roughness is presented. The efficacy of ten different dry surface cleaning materials—including sponges, firm and kneaded erasers, eraser crumbs, a cleaning putty, a solvent-free polydimethylsiloxane elastomer, and a dry swab—have been assessed using a handheld color spectrophotometer and image analysis of photomicrographs. Inspection of the cleaned substrates with a portable optical microscope revealed detailed information into how physical properties of cleaning materials influence the location of residual soot on the surface. 3D digital light microscopy and Fourier-transform infrared spectroscopy were used to assess physical changes to the paper surface and to identify potential residues from the materials after cleaning, respectively. The results of this model study were compared with spot cleaning tests performed on a fire-damaged paper book cover. Limited access to laboratory spaces during Covid-19 lockdown motivated this research to focus on affordable ways to perform hands-on technical research outside of the laboratory, details of which are noted throughout this paper.

RÉSUMÉ

Dans le but de donner des informations détaillées sur le dépoussiérage de la suie, une étude comparant le nettoyage du noir de fumée, servant de modèle pour la suie, sur trois types de papiers de différentes rugosités est présentée. L'efficacité de dix matériaux de nettoyage de surface à sec – qui incluent des éponges, des gommes dures ou de mie de pain, de la gomme en poudre, une pâte nettoyante, un élastomère de polydiméthylsiloxane sans solvant et un coton-tige sec – a été évaluée à l'aide d'un spectrophotomètre portatif et de l'analyse visuelle de photographies prises sous microscope. L'observation des substrats nettoyés à l'aide d'un microscope optique portable a révélé des informations détaillées sur la manière dont les propriétés physiques des matériaux de nettoyage influencent la localisation des résidus de suie sur la surface. La microscopie numérique 3D a été utilisée pour évaluer les changements physiques de la surface du papier et la spectroscopie infrarouge à transformée de Fourier a été utilisée pour identifier de potentiels résidus des matériaux de nettoyage. Les résultats de cette étude ont été comparés avec des nettoyages ponctuels réalisés sur une couverture de livre endommagée par le feu. L'accès limité aux laboratoires de recherche durant le confinement de la pandémie de COVID-19 a orienté l'étude vers des méthodes de recherche appliquée abordables pouvant être faites en dehors des laboratoires, dont les détails sont notés dans l'ensemble de l'article. Traduit par Sophie Barbisan.

RESUMO

Para fornecer informação detalhada para ajudar os conservadores a lidar com a remoção de fuligem, é apresentada uma pesquisa que compara a remoção de pigmento preto de lâmpada, que serve como padrão de fuligem, de três amostras de papel de rugosidades diferentes. A eficácia de dez materiais diferentes para a limpeza das superfícies – incluindo esponjas, borrachas firmes e maleáveis, borracha ralada, um gel de limpeza, um elastômero de polidimetilsiloxano sem solvente e um cotonete ou swab seco – foram avaliados usando um espectrofotômetro de cor portátil e análise de imagem de fotomicrografias. A inspeção de substratos higienizados com o uso de um microscópio ótico portátil revelou informação detalhada sobre como as propriedades físicas de materiais de limpeza influenciam a localização do resíduo de fuligem na superfície. A microscopia de luz digital 3D e a espectroscopia de infravermelho com transformada de Fourier foram utilizadas para avaliar alterações físicas na superfície do papel e identificar possíveis resíduos dos materiais após a limpeza, respectivamente. Os resultados deste estudo modelo foram comparados com testes de limpeza pontual realizados em uma capa de livro danificada em incêndio. O acesso limitado aos espaços de laboratório durante o período de isolamento do COVID-19 motivou esta pesquisa a se concentrar nas maneiras acessíveis de realizar pesquisas técnicas práticas fora do laboratório, cujos detalhes são observados ao longo deste artigo. Traduzido por Sandra Baruki.

RESUMEN

Con el fin de proporcionar información detallada para ayudar a los conservadores que se enfrentan a la eliminación del hollín, se presenta un estudio en el que se compara la eliminación de negro de humo, que sirve como modelo de hollín, de tres muestras de papel de diferente rugosidad. Se ha evaluado la eficacia de diez materiales diferentes de limpieza de superficies en seco – incluyendo esponjas, gomas de borrar firmes y amasadas, migas de goma de borrar, una masilla de limpieza, un elastómero de polidimetilsiloxano sin disolventes y un hisopo seco – utilizando un espectrofotómetro de color portátil y el análisis de imágenes de fotomicrografías. La inspección, de los sustratos limpiados, con un microscopio óptico portátil reveló información detallada sobre cómo las propiedades físicas de los materiales de limpieza influyen en la localización del hollín residual en la superficie. Se utilizaron la microscopía de luz digital 3D y la espectroscopia infrarroja transformada de Fourier para evaluar los cambios físicos de la superficie del papel y para identificar los posibles residuos de los materiales después de la limpieza, respectivamente. Los resultados de este estudio modelo se compararon con las pruebas de limpieza puntual realizadas en una cubierta de libro de papel dañada por el fuego. El acceso limitado a los espacios del laboratorio durante el cierre por COVID-19 motivó que esta investigación se centrara en formas asequibles de realizar investigaciones técnicas prácticas fuera del laboratorio, cuyos detalles se señalan a lo largo de este documento. Traducción: Vera de la Cruz; revisión: Ramón Sanchez, Amparo Rueda.

KEYWORDS:

• Disaster recovery
• cleaning
• residue
• surface roughness
• color spectrophotometry
• Fourier transform infrared spectroscopy
• 3D digital light microscopy
• portable microscope

Acknowledgements

The authors would like to thank Edwin Chan (National Institute of Standards and Technology) for providing Sylgard 184 material and for helpful discussions surrounding how to measure the physical properties of cleaning materials from home. The authors would also like to thank Renate Maile-Moskowitz for providing fire-damaged materials and E. Keats Webb (MCI) for photodocumentation advice. T.D. acknowledges the Smithsonian Postgraduate/Postdoctoral Fellowships in Conservation of Museum Collections Program for funding.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Smithsonian Institution.

Notes on contributors

Teresa T. Duncan

Teresa T. Duncan is a postdoctoral fellow at the Smithsonian Institution Museum Conservation Institute (MCI). She received her PhD in Chemistry from Georgetown University on “Gels from Borate-Crosslinked Partially Hydrolyzed Poly(vinyl acetate)s: Characterization of Physical and Chemical Properties and Applications in Art Conservation” in 2017. Before coming to the MCI, she was a National Research Council postdoctoral fellow at the National Institute of Standards and Technology. Address: Museum Support Center, Smithsonian Institution Museum Conservation Institute, 4210 Silver Hill Road, Suitland, MD 20746, USA. Email: [email protected].

Edward P. Vicenzi

Edward Vicenzi is a research scientist at the Smithsonian Institution’s Museum Conservation Institute (MCI). Before taking-up his position at MCI he served as the Director of the Analytical Laboratories in the National Museum of Natural History’s Department of Mineral Sciences and the co-manager of the Imaging and Analysis Center at Princeton University. He has held professional service positions, including: President of the Microanalysis Society, President of the International Union of Microbeam Analysis Societies, editorial board member for Heritage Science, and editor for Microscopy and Microanalysis (cultural heritage applications). In 2019 he was named a Fellow of the Microanalysis Society. Address: As for Duncan. Email: [email protected].

Thomas Lam

Thomas Lam has a PhD in ceramics from Alfred University, NY. After earning his PhD, he completed postdoctoral employment at the National Institute of Standards and Technology. He is a physical scientist at the MCI, where he applies his knowledge of material science and characterization skills (including SEM-EDS, CL, X-ray fluorescence, and microfade testing) as part of the MCI technical studies team. Address: As for Duncan. Email: [email protected].

Shannon A. Brogdon-Grantham

Shannon A. Brogdon-Grantham is the photograph and paper conservator at the Smithsonian’s Museum Conservation Institute (MCI). She obtained her MS from the Winterthur/University of Delaware Program in Art Conservation where she specialized in photograph conservation with minor concentrations in paper and preventive conservation. She holds a BA in art from Spelman College. At MCI her primary areas of research are understanding historic and contemporary photographic and papermaking techniques, preventive care of photographs and works on paper, characterizing materials used in the manufacture of photographs and paper-based collections, and education and training in photograph and paper conservation for underrepresented communities. Address: As for Duncan. Email: [email protected].