A stabilizer-free non-polar dispersion for the deacidification of contemporary art on paper

The preservation of cellulose-based works of art is threatened by the presence of acidity within the sub-strates, native, i.e., due to the papermaking process, or developed upon aging. The depolymerization ofcellulose catalyzed by acidic compounds leads to a decrease in the mechanical properties of the artworks.Many strategies for hampering the acid-catalyzed degradation of cellulosic substrates have been devel-oped in the past; unfortunately, few of them can be safely used on contemporary artworks, drawings orarchival materials. In this paper, a new method for the pH control of paper, potentially compatible withmost of ballpoint pen drawings and manuscripts, and also safely usable on folded or creased paper, isproposed. A deacidifying dispersion of calcium hydroxide in cyclohexane has been prepared starting fromalkaline nanoparticles obtained via a solvothermal reaction. The most interesting feature of this formu-lation is that a stabilizer is not required for the preparation of a stable dispersion, differently from othercommercial non-polar products. Cyclohexane is a colorless, non-polar, and volatile liquid that allowsfast and simple applications by spraying. In order to evaluate the efficacy of this Ca(OH)2nanoparticlesdispersion in cyclohexane, mockups were prepared on acidic paper using a ballpoint pen. The protectiveaction arising from the applied treatment was evaluated upon artificial aging, measuring cellulose vis-cosimetric polymerization degree (DPv), cellulose pyrolysis temperature, samples pH, and colorimetriccoordinates. The interesting results obtained on mockups led to the application of this new formulationon a series of creased, perforated and burnt drawings from a private collection.