Joint Soft Matter and Chemistry Seminar: Advances in Nanoscience for Art Conservation
Emiliano Carretti, University of Florence
Abstract: Nanoscience is a unique resource to conservation because, unlike conventional materials such as polymers that are commonly used in conservation, engineered nanomaterials do not alter the original physical and chemical properties of artefacts and have low environmental impact. Both hard (inorganic nanocrystals) and soft (built from molecular blocks) nanomaterials can represent a sort of real revolution in the technical approaches to heritage conservation.
Hard nanomaterials are mainly used in the field of Cultural Heritage Conservation, as consolidants and for the deacidification of cellulose-made supports. Recently, a new protocol for the consolidation of bone remains based on the use of HAP nanoparticles was developed and the consolidation performance of this new treatment was evaluated by applying it to degraded ancient bone findings. The new consolidation method was also tested to assess possible effects on two typical molecular analyses performed on ancient bones, named palaeogenetic analysis and radiocarbon dating. Furthermore, preliminary results indicate that nanomaterials seem to be a promising tool also for the remediation of the “vinegar syndrome”. This phenomenon that affects motion picture films made of cellulose triacetate concerns the side-chain cleavage through ester hydrolysis induced by moisture, with the formation of hydroxyl groups and the release of acetic acid. glycosidic bonds between the glycosidic units constituting the CTA backbone. Then, in addition vinegar syndrome’s macroscopic symptoms are the shrinkage and the embrittlement of the film and a consequent detachment of the emulsion.
Moreover, soft nanomaterials (gels, and liquid dispersed systems like micellar solutions and o/w microemulsions) are used as innovative cleaning tools for painted surfaces of historical and artistical interest. Being the cleaning one of the most important steps during a conservation/restoration workshop, an approach based on the nanotechnologies can represent a possible innovative alternative to traditional methods mainly based on the application of pure organic solvents. In that way it is possible to warrantee at the same time the minimization of the environmental impact, a high selectivity and also the possibility to control the cleaning action.
-E. Carretti, L. Dei, P. Baglioni, R. G. Weiss, Synthesis and Characterization of Gels from Polyallylamine and Carbon Dioxide as Gellant, J.Am.Chem.Soc., 2003, 125, 5121.
-E. Carretti, L. Dei, R. G. Weiss, Soft matter and art conservation. Rheoreversible gels and beyond, Soft Matter, 2005, 1, 17.
-E. Carretti, E. Fratini, D. Berti, L. Dei, P. Baglioni, Nanoscience for Art Conservation: o/w microemusions embedded in a Polymeric Network for the Cleaning of Works of Art, Angewandte Chemie, 2009, 48, 8966.
-E. Carretti, M. Bonini, L. Dei, B. H. Berrie, L. V. Angelova, P. Baglioni, R. G. Weiss, New Frontiers in Materials Science for Art Conservation: Responsive Gels and Beyond, Accounts of Chemical Research, 2010, 43, 751.