Polyvinyl alcohol based hydrogels as new tunable materials for application in the cultural heritage field

Hydrogel-based cleaning of paper artworks is an increasingly widespread process in the cultural heritage field. However, the search for tuned (compatible, highly retentive and not perishable) hydrogels is a challenging open question. In this paper, a complete characterization of chemical hydrogels based on polyvinyl alcohol (PVA) crosslinked with telechelic PVA and their remarkable performances as gels for cleaning paper artworks are reported. The rheological properties, porosity, water content of these gels were determined and analyzed as a function of the components concentration during synthesis. Due mechanical and retentive properties, the reported gels are optimum candidates for paper cleaning applications. The efficacy of these PVA-based gels has been demonstrated applying them on the surface of the sheets of several paper artworks, and characterizing the samples before and after the cleaning process by means of a multidisciplinary approach involving spectroscopic and chromatographic tests.