New advances in the development and testing of green cleaning materials for cultural artefacts

Silvia Prati (Università di Bologna, Department of Chemistry G. Ciamician, Via G. Guaccimanni 42 48121 Ravenna, Italy, s.prati@unibo.it)

The removal of thin degradaded coatings from cultural heritage artefacts has always been particularly challenging since it requires the use of selective systems capable to act on few microns thick layers without affecting the above matrix which may be chemically similar to what has to be removed. This need leaded to the development of selective systems in which the solvent is confined in a medium in order to garantee a controlled release in order to avoid leaching and swelling effects on the artefact.Recently in the field of restoration there has also been an increasing demand related to the development of new green methods which are safe both towards the operator and of the environment.In this context my research group has so far developed different cleaning formulations obtained with biopolymers such as polyhydroxybutirate and agar in combination with green solvents for the selective removal of different types of unwanted coatings from several types of artistic artefacts such as movable and immovable paintings, metal objects, paper substrates, cinematographic movies [.Recently the combination of green gels and adavanced electrospun tissues have shown an increase of the performances of the cleanig systems in terms of effectiveness, and ease of application. In particular these combined systems applied on paintings allow to exploit a peeling effect which avoid any further mechanical treatment after the removal of the coating.Tailored formulation of green gels and advanced tissues are actually in development for their applications in the frame of the national project Superstar (coordinated by the University of Pisa) and the european one GOGREEN (coordinated by the Univeristy of Amsterdam).In the frame of the Superstar project new functonalised innovative tissues are actually under evaluation to remove vandalic paints applied over Street Art. In the frame of the GOGREEN project, the focus is related to the removal of terpenic and acrylic coatings form paitings and tarnishing from silver objects with the use of green gels and new advanced tissues.

Bibliography

[1] Lozano, M.V.C., Sciutto, G., Prati, S., Mazzeo, R., Deep eutectic solvents: green solvents for the removal of degraded gelatin on cellulose nitrate cinematographic films (2022) Heritage Science, 10 (1), art. no. 114, .

[2] Jia, Y., Sciutto, G., Botteon, A., Conti, C., Focarete, M.L., Gualandi, C., Samorì, C., Prati, S., Mazzeo, R. Deep eutectic solvent and agar: a new green gel to remove proteinaceous-based varnishes from paintings (2021) Journal of Cultural Heritage, 51, pp. 138-144.

hydrophobic (linseed oil as binder) and hydrophilic (egg temperas as binder) surfaces. The procedure

[3] Jia, Y., Sciutto, G., Mazzeo, R., Samorì, C., Focarete, M.L., Prati, S., Gualandi, C. Organogel Coupled with Microstructured Electrospun Polymeric Nonwovens for the Effective Cleaning of Sensitive Surfaces (2020) ACS Applied Materials and Interfaces, 12 (35), pp. 39620-39629

[4] Yiming, J., Sciutto, G., Prati, S., Catelli, E., Galeotti, M., Porcinai, S., Mazzocchetti, L., Samorì, C., Galletti, P., Giorgini, L., Tagliavini, E., Mazzeo, R. A new bio-based organogel for the removal of wax coating from indoor bronze surfaces

(2019) Heritage Science, 7 (1), art. no. 34, .

[5] Prati, S., Sciutto, G., Volpi, F., Rehorn, C., Vurro, R., Blümich, B., Mazzocchetti, L., Giorgini, L., Samorì, C., Galletti, P., Tagliavini, E., Mazzeo, R. Cleaning oil paintings: NMR relaxometry and SPME to evaluate the effects of green solvents and innovative green gels (2019) New Journal of Chemistry, 43 (21), pp. 8229-8238.

[6] Prati, S., Volpi, F., Fontana, R., Galletti, P., Giorgini, L., Mazzeo, R., Mazzocchetti, L., Samorì, C., Sciutto, G., Tagliavini, E. Sustainability in art conservation: A novel bio-based organogel for the cleaning of water sensitive works of art (2018) Pure and Applied Chemistry, 90 (2), pp. 239-251.

[7] Samorì, C., Galletti, P., Giorgini, L., Mazzeo, R., Mazzocchetti, L., Prati, S., Sciutto, G., Volpi, F., Tagliavini, E. The Green Attitude in Art Conservation: Polyhydroxybutyrate–based Gels for the Cleaning of Oil Paintings (2016) ChemistrySelect, 1 (15), pp. 4502-4508.

https://zoom.us/j/98578019100?pwd=VkI3Vk5pVUY1amlCR0ZCV0hqNFQ5dz09