Degradação de materiais constitutivos da fotografia sobre vidro: estudo da coleção Barão Von Tiesenhausen

Abstract

This work established as the focal point the "study of constructive technique" of glass negatives plates, from which the research was based. Through scientific, analytical and methodological means glass negative plates collection of Barão von Tiesenhausen belonging to Abilio Barreto Historical Museum, was analyzed. The small amount ofresearch on preservation of photographic collections in Brazil can be linked to the fact that training in conservation is a relatively new field, and even more so in the case of photographs conservation. National studies on this type of collection are usually restricted to the field of description photographic processes and preventive conservation measures (temperature and humidity control, storage and displaying), without sticking, however, the aspects linked to the analysis of materials and building technology, facing the problem of preservation of photographic collections which is related unfamiliarity to photographic physical and chemical structure and their interaction with the environment. Faced with such complexity, this research aims not only to study, analyze and document the construction techniques and materials present in twelve glass negatives plates that make up the "Baron von Tiesenhausen" collection, but also evaluate the intrinsic degradation factors associated with the interactions of the chemical components found in the structure of materials, and the deterioration caused by the chemical and physical reactions of these components with the external environment. All this work was done with the aid of scientific methods used in the analysis in such objects. Accordingly, we approached each of the tests used, themethodology used for these analyzes, and the purpose of each one of them. Also, based on the glass negative plates collection study, we correlated the materials used in manufacturing processes, as well as degradations present with the glass negative plates elements found in the analyzes, considering in the latter case, the silver mirroring. Asexpected, these analyzes indicated the components present caused by silver mirroring, helping to understand not only the formation mechanism of this type of degradation, but also its causes. Moreover, some components were detected, whereby it was possible to determine the technique of negative - gelatin. Thereby we demonstrated how scientificanalysis used are of great importance in photographic technique identification and its dating. And how this scientific method of analysis can determine the performance of the professionals involved in the conservation of this type of collection, assisting in understanding of aging and degradation of constructive technique employed in it.