Catalytic nanoceria applied in the protection of Roman frescoes

Ancient frescoes undergo complex degradation phenomena that irreversibly alter the surfaces and compromise the structural integrity, putting at risk the historic and cultural legacy from the past. To answer these challenging issues, a formulation based on cerium oxide nanoparticles (CeO2-x NPs) can be ideal. In this work, an optimized microwave-assisted synthetic protocol was developed and studied to produce highly uniform NPs, which have been characterized with advanced characterization techniques. A chitosan formulation was optimized by modifying some dispersions parameters, focusing on the concentration of polymer. This formulation was applied onto mock-ups especially designed to replicate Roman frescoes and preliminary tests (color alteration, surface morphology, rheology, and protection factor) were implemented.