| Abstract |
In this degree project it was examined the application of specific compounds with regard to the physical and chemical properties of the most frail member of the mineral family of gypsum in the form of structural parts of the Minoan monuments of Knossos, aiming to the restoration of the deteriorated stone surfaces. The predominant weathering forms that occur on Minoan gypsum were classified and described with respect to the crystallographic and tectonic characteristics of the material and the factors and mechanisms of deterioration. The chemical compounds studied, are silicic acid polymers in specific methyltrimethoxysilane (MTMOS) and tetra-ethoxysilane (TEOS). At the same time, a polymer compound of methacrylate acid in the form of organic dispersion was applied. The goal of the application of the above compounds was to study the results of those compounds in their commercial forms, in relation to the discontinuities formed on the surface layers of the architectural elements made out of coarse crystal selenite as a result of deterioration. The initial datum for the quantitative determination of the consolidating material deposited in the mass of the mineral samples, came from the difference of the dry weights before and after the application of the consolidants. The next step was the examination of the untreated samples with the method of X-ray difraction (XRD) in order to investigate the possibility of the presence of clay minerals within the tectonic matrix of the studied selenites which would affect the dispersion of the consolidating materials. Under the same prism, samples out of the products of deterioration process were studied. The qualification of the penetration degree of the consolidants in the crystal matrix of the deteriorated stone, was achieved by monitoring the presence of their products formed after the polymerization. In this preliminary stage, the presence of the consolidation material was qualified after optical observation through scanning electron microscope (SEM) images, while the qualitative qualification was achieved through the chemical characterization of the formed material, through the acquisition of Energy-dispersive X-ray spectras (EDS). Finally it must be noted that for the purposes of this project, samples of coarse crystal selenite were accuired out of the the gypsum outcrops of the ancient quarry in the “Gypsades” region southwest of the Knossos archeological site.
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Χημικές προσεγγίσεις στην προστασία γυψόλιθων (θεϊκό ασβέστιο) του παλατιού της Κνωσού από περιβαλλοντική διάβρωση
