Mixing Chemistry and Art

Bridging the interface between art conservation and chemistry education, this work presents an innovative science learning experience derived from the practice of art conservators. The safe removal of aged varnishes and overpaint from artworks without damaging the original paint hinges on the precise utilization of solvent mixtures that navigate solubility differences between unwanted coating and the original paint. However, differential evaporation rates of the solvent components from the artwork surface can compromise these mixtures, leading to too aggressive dissolution or ineffectively weak mixtures. Learners can delve into the scientific aspects of art conservation by focusing on azeotropic solvent blends, specifically those of isopropanol with n-hexane and 2-butanone with cyclohexane, which should evaporate at a constant composition. Using methodologies like gravimetric analysis, refractive index, vapor pressure measurements, and gas chromatography, students observe the compositional changes of these blends during evaporation at room temperature. Inspired by research at the Indianapolis Museum of Art, this learning experience emphasizes the hands-on application of chemistry in art conservation.