Papers by Keyword: Ancient Ceramic Tiles

Abstract: The application of Ion Plating Plasma Assisted technology in the field of preservation of Cultural Heritage is presented. In order to guaranty the preservation of the artistic and cultural identity of ancient ceramic tiles with strong chromatic valence, not-invasive, and achromatic and antireflective coating deposition processes have been investigated. Different ceramic supports have been utilized for the tests: an ancient tile of the XIX century and contemporaneous production tiles, all characterized by strong chromatic valence and by a mixed porous and glazed surfaces. Ion Plating Plasma Assisted (IPPA) by reactive magnetron sputtering source with Argon and Oxygen atmosphere for TiO₂ and IPPA by thermal source with Argon and Oxygen from SiO material have been adopted. Preliminary tests with two plasma treatments were carried out on contemporaneous tile samples in order to find the optimal processing conditions. TiO₂ treatment has generated miscoloration on the surface of the coating while the SiO₂ coating showed achromatic and transparency properties. The ancient historical tile was used to finally test the optimized process with SiO₂. Traditional organic resin spray coating treatments have been carried out for aesthetical comparative purposes with the new plasma treatment.

Abstract: Ancient ceramic wall tiles, called “azulejo”, firstly used on Portuguese churches, monasteries and palaces (15-18th century) have progressively been used in particular houses till the last century. These tiles and its use in huge decorative panels can be considered as a precious but fragile cultural heritage from Brazil to India, in several countries influenced by Portuguese culture. Morphologically, these tiles are composed by a porous clay-based ceramic body, the terracotta, covered by a protective glassy phase, the glaze. As artistic paintings, these murals incorporated various kinds of pigments in the glaze layer to create a pictorial impact on the walls of rich palaces or churches, real and durable monumental works-of-art. In the 21st century, degradation marks are visible on these ceramic tiles because of their use under corrosive conditions (moisture, atmospheric cycles…) along centuries. In order to promote their conservation and enhance their restoration, the physical-chemical characterization of the azulejos is performed in the present work, using mainly non-destructive processes like micro-Raman spectroscopy or X-Ray diffraction. In particular, Raman spectroscopy allows the detection of some nano/microcrystals present in the amorphous glaze due to pigments or opacifying agents or related to the elaboration process of the azulejo. Based on the observation of various selected fragments, one states that very few pigments have been used as colouring agents in this ceramic art during 17-18th centuries. Thus, the relationship between the different colours, the introduced pigments and the structural aspects of the glass will be focused. Some features related with the ancient ceramic technology will also be discussed.