Confined Aqueous Media for the Cleaning of Cultural Heritage: Innovative Gels and Amphiphile-Based Nanofluids

This chapter presents the applicative potentialities of gels for the cleaning of artworks surfaces. In particular, innovative physical and chemical gels, with high water retention capability, high responsiveness to external stimuli, and suitable mechanical properties, are described. The high solvent retention capability and the specific mechanical properties of these gels allow the safe cleaning of artifacts, even including water-sensitive substrates. In fact, the cleaning action is limited to the contact surface, and the complete removal of soil is achieved while avoiding solvent spreading and absorption within the substrate. In particular, the use of gels based on semi-interpenetrating (IPN) polymer networks provides great advantages because these gels are able to load water-based detergent systems, such as micellar solutions and microemulsions, which are effective in removing synthetic adhesives and highly hydrophobic detrimental materials. The combination of semi-IPN polymer networks with these detergents allows the cleaning of sensitive substrates such as canvas paintings and manuscripts.