An innovative and sustainable approach to spray paint graffiti removal from Istrian stone through the silica sol-gel chemistry: A preliminary assessment

A sustainable methodology to synthesise and screen libraries of new low-environmental impact products, suitable for removing graffiti and murals from historic building, masonries and stone artworks has been developed. This approach provided a novel series of two-component systems by combining silica sol-gel chemistry and dimethyl carbonate. The solid matrixes were hybrid silica gels, which were synthesised in basic conditions by using ethylene and propylene glycols as organic co-solvents. Dimethyl carbonate (DMC) was the green organic solvent to load into the gel. The efficiency of three new systems in adsorbing/trapping commercial red aerosol spray paint was investigated through an ad hoc test tube extraction evaluation and on mock stained samples of Istrian stones. Data provided byNMRspectroscopy and FT-IR spectroscopy led to the identification of a promising cleaning agent, paving the way to its full characterisation and features improvement.A sustainable methodology to synthesise and screen libraries of new low-environmental impact products, suitable for removing graffiti and murals from historic building, masonries and stone artworks has been developed. This approach provided a novel series of two-component systems by combining silica sol-gel chemistry and dimethyl carbonate. The solid matrixes were hybrid silica gels, which were synthesised in basic conditions by using ethylene and propylene glycols as organic co-solvents. Dimethyl carbonate (DMC) was the green organic solvent to load into the gel. The efficiency of three new systems in adsorbing/trapping commercial red aerosol spray paint was investigated through an ad hoc test tube extraction evaluation and on mock stained samples of Istrian stones. Data provided by NMR spectroscopy and FT-IR spectroscopy led to the identification of a promising cleaning agent, paving the way to its full characterisation and features improvement