Berlin 2012 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 23: Poster: Polymer Dynamics
CPP 23.6: Poster
Mittwoch, 28. März 2012, 11:00–13:00, Poster A
Experimental and theoretical study of the yellowing of ancient paper — Adriano Mosca Conte1, Olivia Pulci1,2, Arkadiusz Knapik3, Jacek Bagniuk3, Joanna Łojewska3, and •Mauro Missori4 — 1ETSF, Dept. of Physics, Università di Roma Tor Vergata, Rome, Italy — 2Institute of Structure of Matter, National Research Council, Rome, Italy — 3Faculty of Chemistry, Jagiellonian University, Krakow, Poland — 4Institute of Complex Systems, National Research Council, Rome, Italy
Paper has been the most widely used writing support since the Middle Ages. The preservation of ancient books and documents must be based on an advanced knowledge of the paper degradation processes. Yellowing causes major damage for the aesthetic appearance of ancient paper and it is due to cellulose oxidation, a complex process with many possible products, some of them chromophores, still to be clarified. In this talk, we will present experimental ultraviolet-visible spectra of ancient papers of the 15th century and, as reference, modern samples artificially aged under different environmental conditions. With the aid of ab-initio Time-Dependent Density Functional Theory calculations, we investigate several possible oxidized forms of cellulose polymers. Through the comparison of measured and calculated optical spectra, we identify those oxidized groups which act as chromophores. Our non-destructive approach could be used as a powerful method to estimate the state of degradation of historical papers and in the research of bleaching and reducing agents to be employed in the restoration practice.