A Comparison of Solvent Application Techniques on Oil Paint Samples

Hi, my name is Allison Kelley and I will be researching the effects of solvent ingress on paint samples this summer in Dr. Meldrum’s lab in the Chemistry Department. As a lover of art and art history, the conservation of paintings is an area of great interest to me, and I am so excited to have the opportunity this summer to contribute to the conservation field through my research. Paintings often have to be cleaned as a part of the conservation process, and this process involves applying an organic solvent to the surface of the painting to remove build-up from the varnish layer. The aim of this project is to compare two different methods of solvent application on paint samples which have been varnished in order to test the potential benefits of a newly suggested method against a more commonly used technique. The more general method used in the conservation world involves simply applying the solvent directly to the varnish via a cotton swab. The second method, which has been suggested as a less invasive technique, first requires a thickening of the solvent by adding hydroxypropyl cellulose giving the solvent a gel-like consistency. This gel is then applied to the sample via a tissue that has been saturated with the thickened solvent; pressure is then applied in a relatively uniform manner. Using NMR techniques, a profile of the paint samples, both before and after the solvent application, will be measured to observe the depth to which the solvent penetrates and the effect it has on the varnish. The data from the dry sample will be subtracted from the data for the sample after solvent application thus allowing only the signal that is attributed to the solvent to be observed. We hope that the data from this profiling will bring insight about the proposed benefits and effectiveness of the thickened-solvent application method. This project will also be beneficial in refining the NMR techniques used to create these types of depth profiles, facilitating their application to other systems in the future.