Confinement of organic solvents in gel matrices for the cleaning of works of art

Despite the crucial socioeconomic role of cultural heritage, its preservation remains a relatively niche application in science. We show here representative examples illustrating how recent advances in colloid and soft-matter science can support cultural heritage conservation, with emphasis on “green” and sustainable systems designed to confine neat organic solvents or solvents in complex fluids for the cleaning of artworks. Strong connections are highlighted among material design, application strategies, and the underlying physicochemical processes, to demonstrate how addressing conservation challenges can generate insights transferable to a wide range of scientific fields. Representative artworks are considered, from wall and easel paintings to paper. Several classes of synthetic polymers—such as acrylates, acrylamides, poly(vinyl alcohol), poly(ethyleneimine), siloxanes, and thermoresponsive systems like poly(N-isopropylacrylamide)-based microgels—have demonstrated effectiveness for confining solvents and warrant further investigation. In parallel, a growing body of bio-derived gel materials is being growingly explored, including agar, acrylated gellan, alginate, Funori (combined with halloysites), poly(vinyl butyral), polyhydroxybutyrate, and, recently, castor oil. The examples and perspectives presented here, which represent the most recent advances in the field and introduce novel developments with the potential to drive scientific progress across multiple sectors, demonstrate that, when guided by a Safe-and-Sustainable-by-Design (SSbD) approach, soft matter and colloids for cultural heritage preservation can transform from an expanding niche field into a source of inspiration with broad, transversal impact, encompassing both theoretical and applied domains.