Angela C. Santamaria participated in the 7 th International Congress Chemistry for Cultural Heritage2024 held in Bratislava from 02 nd to 07 th July 2024. She presented a poster titled “Effectiveness of different chemical cleaning methods to remove graffiti from ornamental stones: the case of varying organic solvents concentrations and poultices”.
The chemical removal of graffiti from ornamental stones is a common practice in the conservation of Cultural Heritage. In this study, low-toxicity organic solvents were mixed at different concentrations and applied using various delivery systems to remove black acrylic graffiti from four natural stones with different compositions and textures. Analytical techniques, including spectrophotometry, stereomicroscopy, Raman spectroscopy, and Scanning Electron Microscopy with Energy Dispersive X-Ray analysis (EDX) analysis, were employed to evaluate the cleaning effectiveness on these stones.
The results demonstrated that graffiti removal effectiveness is largely dependent on the stone’s texture. Graffiti was more successful removed from polish surfaces, such as granite and diorite compared to more porous stones like travertine and Pietra di Luserna, regardless of the delivery system used.
For diorite, granite and Pietra di Luserna, the most effective cleaning results were achieved using a solvent mixture consisting of 51% ethyl alcohol, 38% isooctane and 11% acetone, while for travertine the best results were achieved with a mixture of 1% ethyl alcohol, 96% isooctane and 3% acetone.
Acknowledgements: This research was funded by the Spanish research projects CNS2022-135645 and RYC2020-028902-I.
