Dual physically and chemically crosslinked regenerated cellulose – Gelatin composite hydrogels towards art restoration

Art restoration poses many challenges for scientists and conservators, as any restorative action can lead to lasting modification or damage to the original artefact. Recent interest in gel encapsulation has grown due to the ability to control the cleaning action; yet the restoration of modern paints such as acrylic-based systems still presents issues due to their extremely high sensitivity to most solvents. Herein, the preparation of dual physically and chemically crosslinked hydrogels based on regenerated cellulose and cinnamoyl-modified gelatin is demonstrated. These dual crosslinked hydrogels show increased mechanical strength and enhanced water retention compared to pure physically crosslinked hydrogels. When applied to acrylic-based paint surfaces, the dual crosslinked hydrogels extract a smaller amount of hydrophilic additives (albeit still leading to swelling within the paint film) versus physically crosslinked gels. It is anticipated that this dual crosslinking approach can be broadly applied to prepare gels for conservation of cultural heritage artefacts.