Dr Lora Angelova, Newton International Fellow, Department of History of Art, University College London, présentera ses recherches lors d’un séminaire au LAMS (salle de réunion, tour 33, 3e étage) le mardi 23 juin à 10h.
Gel Systems in Cultural Heritage Conservation - Development of New Materials and Exploration of Available Systems
Short Abstract :
Over the past three decades, thickened and gelated solvents have been introduced to the conservation community as alternatives to free solvents for the surface cleaning of artworks. The materials span a wide range of rheologies (from thixotropic to shear-thickening) and gelation mechanisms ; they can be composed from bio and synthetic polymers, can gelate organic solvents, aqueous cleaning agents such as enzymes or chelators, and have recently been combined with emulsions. For many years, conservators have been taught that the gels acts as poultices, simply delivering liquid to the surface ; the gel network was deemed ’inert’ with respect to the cleaning action of the gel. Recently, these ideas have started to change, and the role of the gel network and its interactions with the artwork surface have become a topic of interest.
This talk will cover some of the main issues around the use of gels for conservation treatments and briefly describe the process of developing one gel system for the conservation community. Several research groups are working on developing novel gel systems for conservation ; however, there are limited studies comparing the properties of currently available gel systems. Using unilateral NMR spectroscopy, we have been studying a critical characteristic of gel treatment systems - their ability to limit diffusion of the solvent into paint layers - for a range of gels available to conservators. The results from studies on acrylic paints will be presented. Additionally, sum frequency generation spectroscopy, which may be useful for the study of gel-network/artwork surface interactions will be discussed and preliminary results obtained in the treatment of a PMMA surface with a poly(vinyl alcohol)-based gel will be presented.
Author background :
Lora Angelova obtained a PhD in chemistry from Georgetown University in collaboration with the National Gallery of Art, Washington, D.C., working under the joint mentorship of Richard Weiss and Barbara Berrie. She is currently a Newton International Fellow, spending one year in the Department of Chemistry at the University of Cambridge, and one year in the Department of History of Art at the University College, London.