Materials and Methodologies for Spectroscopic and Optical Analytical Applications in Cultural Heritage Conservation Science

Abstract

The field of conservation science falls in the intersection of science and art. The work of conservation scientists may include any single subdiscipline of chemistry, though it is most commonly a highly interdisciplinary field taking skills from analytical, organic, and inorganic chemistry, as well as surface and materials science. The aims of conservation scientists are to answer questions about the production and aging of material cultural heritage. Knowing the materials used by an artist can lead to insight about the intentions of the object and knowing how those materials degrade will enable the use of preventative measures to ensure the object can be enjoyed for future generations. All conservation science work aims to inform collections care personnel (e.g., conservators and curators) so that they can implement appropriate care, storage, and display conditions for a given object. Special considerations must be made when analyzing artwork. Such considerations include leaving an object in the same condition it was in before treatment, and when sampling is necessary, minimizing the sample size to the greatest extent possible. Therefore, an important facet of conservation science work is to ensure techniques are as non-destructive and minimally-invasive as possible. In this work, two applications to conservation science are presented. The first application aimed to identify red colorants on Japanese woodblock prints by novel sampling and analytical methods. The inception of this project was in partnership with the Portland Art Museum (PAM) and the 2018 exhibition entitled Suzuki Harunobu and the Culture of Color. The work herein developed a soft mechanical sampling technique for the acquisition of micrometer-sized colorant particles from the surface of 18th century woodblock prints. In Chapters 3 and 4, the sampling method is introduced and validated, and the collected samples were analyzed by surface-enhanced Raman spectroscopy (SERS). The analysis was aided by the implementation of a genetic algorithm (GA) which matches the spectral contributions of the samples to identify the components present. In Chapter 5, the results of a study of artworks attributed to Suzuki Harunobu in the PAM's permanent collection are presented. Through a multi-analytical approach, the palette of red colorants in the collection was established. This work provides technical information and historical context to the practice of commercial printmaking in late-18th century Japan. The second application, presented in Chapter 7, aimed to develop a sensor for the detection of active corrosion products on the surface of metal sculpture. This work provides the