Project Researchers: Lora Angelova, Stefani Kavda and Bronwyn Ormsby (Tate)
Project Funders: The Royal Society Newton Fund and Qatar Foundation
Works of art and artefacts are frequently subject to soiling and the accumulation of surface deposits during their lifetime. Handling, display and storage environments each impact on the surface nature of an object, and alterations in the underlying chemistry of the materials of construction, such as migration of additive materials in plastics, may also cause surface modifications that are distracting for the viewer and exacerbate the adhesion of particles.
An increasing number of gel systems are being introduced to the conservation community as a means to deliver liquids to the artwork surface during cleaning treatments in a controlled and effective manner. As with all wet cleaning protocols, when a gelated liquid is brought in contact with sensitive and precious objects, of primary concern is the ability to control its diffusion both laterally and orthogonally so as to affect only the targeted area and to limit, and ideally eliminate, the deposition of residues from the gel network on the treated artwork. Both of these factors are likely to depend on the interactions between the gel system and the surface of the artwork - a topic that has largely been unexplored. Considering the dynamic nature of such soft matter systems, the macromolecules that make up the gel network will orient themselves at the artwork interface to maximize favourable interactions, a process which may aid in solubilization or affect the rate of solvent ingress into the artwork surface. Our current research aims to begin addressing some of these complex questions in an effort to better understand the processes taking place during a gel cleaning campaign.
Bulk diffusion of liquid from gels into acrylic paint films and plastics is being studied using single-sided NMR spectroscopy. Sum frequency generation spectroscopy is being used to investigate the interfacial interactions between the polymer network and the top-most molecular layer of the paint surface. Finally, fluorescence lifetime measurements will be used to study the solvent dynamics at the gel-surface interface.