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Nathan Ferrandin Schoffel (SIMM)
Aminosilanes as a one-pot treatment for simultaneous deacidification and strengthening of heritage papers
Acidity is a major issue in the preservation of paper-based collections. A large number of paper documents of mediocre quality produced in the late 19th and early 20th century are very acidic and brittle, their public access hence being drastically restricted. To find a solution for these documents, treatments based on copolymerized aminoalkylalkoxysilanes (AAASs), which allow simultaneous deacidification and mechanical strengthening of paper, have been developed at Centre de Recherche sur la Conservation (CRC) and Laboratoire de Physicochimie des Polymères et des Interfaces (LPPI). As these treatments showed efficacy for some papers but not for others, the results had to be better understood before a possible use by the conservation professionals.
My PhD project (2017-2021) advanced the understanding of the interactions/reactions between AAASs and the cellulosic substrate, with a better identification of the parameters that reduce the treatment efficacy. To that purpose, AAAS treatments were applied to newsprint lignocellulosic papers of complex compositions, and NMR and FTIR were used to characterize the physicochemical bonds formed in-situ. In conjunction, the evolution of the physicochemical properties (pH, optical and mechanical properties) of a large range of papers treated several years ago were studied. Finally, several options for optimized formulations of the AAAS treatments were tested, including the use of reducing and deacidifying agents as pre-treatments for paper and thermal post-treatment sequences.