Estudos arqueométricos e de conservação preventiva do patrimônio cultural de papel

Abstract

Cultural heritage includes, mostly, ancient materials that must be preserved, and that are subjected to deterioration. Preventive conservation is the best way to protect the materials, and, for that purpose, it is necessary to have suitable knowledge on analytical methods for each specific damage on the materials. Archaeometry can offer a wide range of possibilities that can contribute for the study, conservation and treatment of the cultural heritage. Thus, the aim of this study was to investigate the use of various archeometric tools for the preservation and preventive conservation of cultural heritage of paper. In the first chapter, a study of the microbiota present in specialized public library was characterized via classic microbiology and molecular biology and the inhibitory concentration of a chemical compound was stablished on the growth of the single species. The results indicated the lack of cross contamination in the library and a good efficiency of ortophenylphenol as a fungistatic agent in the concentration of 400 mg.L-1. In the second chapter it was studied iron-gall inks prepared from hydrolysable and condensed tannins, at different iron concentrations, using scanning electron microscopy (SEM) technique as research to observe nonreactive iron deposits in paper surface, and it was determined by chemical tests, the content of total and condensed tannins in the inks, to confirm the results obtained by SEM.The results indicated that in the first simulation hydrolysable tannins from Castanea sativa and Caesalpinia spinosa were more stable due to the higher reactivity with iron, while condensed tannins from Acacia sp. presented reduced reactivity, contributing for the formation of aggregates in the surface of paper strips, leading to the conclusion that degradation patterns could be explained in terms of reactivity. Beyond this, the determination of tannins concentration explained the formation of aggregate particles by microscopy. In chapter three a study with the help of atomic absorption spectrometry (AAS), desorption of non-removal iron for four iron gall inks with different concentrations of iron was conducted, evaluating the kinetics of iron-removal for two calcium phytate solutions applying pseudo first-order and second-order models. The results presented an iron kinetics removal around 15 minutes for both phytate solutions. The most diluted calcium phytate solution proved to be as efficient as the most concentrated solution. Pseudo first-order equation fit experimental data more precisely, thus confirming the rapid kinetics, confirming the possibility of introducing simultaneous baths in a wide range of documents. In chapter four, eight different types of paper were studied with respect to its capacity to impregnate iron gall ink, the non-reactive iron accumulation and fungal attack susceptibility. The EAA and SEM techniques showed that the interaction of inks with the papers directly depends on the particular characteristics of these supports. Furthermore, the chemical corrosion caused by the use of iron gall ink favored microbiological corrosion by fungi in all types of paper