Gold medal award for Innovation in joint work between CENIMAT|I3N and REQUIMTE

Work titled "New formulations of enzymes and Ionic liquids for removing protein-based materials from painted and polychrome works of art" by  C. Pereira, I.C.A Sandu, L.C. Branco, T. Busani won the gold medal award for innovation during EuroEvent conference.

New formulations using a combination of enzymes (three different proteases) and ionic liquids are proposed for the removal of proteinaceous varnish layers (egg white, animal glue, isinglass and casein). The treatment was applied on documented reconstruction of painted surfaces and gold leaf gilding.

The use of ionic liquids (ILs) defined as “green solvents” as an alternative solvent to enzymes is an area in conservation science with a large number of possibilities: the ionic liquid is a material that can be designed (cation-anion combinations) to adjust to different requirements such as improvement of enzyme cleaning effectiveness, surface compatibility, and safety for the user.

To monitor and analyze the effectiveness of each formulation, a novel multi-scale non-invasive approach based on four different analytical techniques: colorimetry (CIE L*a*b*), optical microscopy (OM) with visible and fluorescence light, atomic force microscopy (AFM) and scanning electron microscopy (SEM) was applied. The combinations of these techniques allowed an extensive and complete view of the surface material and its characteristics/behavior. Going to a nano-scale with the use of AFM proved to be of major importance to achieve a new further level of information; at the same time the conclusions were easily extrapolated to a larger scale.