Agenda

Emiliano Carretti, Chemistry Department 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.
In particular 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.
The application of new safe systems with very low environmental impact like liquid or gelled oil-in-water microemulsions or micellar solutions as alternative to pure organic solvents is one of the innovative solutions purposed for the extraction of polymeric resins from the surface of natural and artificial stone materials (their presence strongly alters the physicochemical properties of the interface between the work of art and the environment and their natural aging can lead to undesired side effects, usually in a period of 20-30 years from the application that make mandatory their removal). Furthermore, in the conservation of easel paintings, problems related to the direct application of pure organic solvents to painted surfaces (such as swelling of the binding media and original varnish layers) can also be drastically reduced when the liquids are applied as gels. Trying to minimize the amount of gel residues left on the paint surface after the application and the removal of the cleaning tool, recently, the synthesis of a new class of “intelligent” organogels, is one of the most actual challenges in the field of Conservation Science.