Amphiphile-based nanofludis for the removal of styrene/acrylate coatings: Cleaning of stucco decoration in the Uaxactun archeological site (Guatemala)

The conservation of mural paintings, stone and stucco elements, which are present in archaeological sites, may involve the removal of synthetic polymers used in the past as consolidants or protective agents. Unfortunately, traditional cleaning methods do not provide satisfactory results in this case. Micelles and microemulsions are the most effective alternative to the use of traditional organic solvents. In this contribution, we report the results of laboratory and in situ cleaning tests on specimens and works of art, whose surface was coated with Sokrat® (also known as Axylat®). Polymer removal was performed with a microemulsion that was previously used to efficiently remove Paraloid B72® from inorganic porous substrates. The good results obtained in laboratory were confirmed by the cleaning test on the stucco decorations in the Uaxactun archaeological site (Guatemala). Finally, SAXS characterization of the nanofluid before and after the interaction with Sokrat® showed that micelles reorganize and get smaller due to the solvents’ migration from the aggregates to the polymer. This behavior is in agreement with previous results obtained on this and other microemulsions interacting with different polymeric films.