The application of analytical techniques, initially developed in the field of materials sciences, to art and heritage objects gives historians the possibility of obtaining information about its material composition. From this information, it is possible to respond in a grounded manner to some questions about the origin and methodology of production of these objects.
\r\nThis type of analysis is also valuable and sometimes crucial in the decisions of the conservator, namely in the differentiation of original parts of an object, later additions, identification of restorations and even possible falsifications.
\r\nThe phenomena of degradation to which these objects are exposed can be studied with these techniques and, in this way, the conservator will be able to understand the kinetics of deterioration and to develop treatments and ways of preventing or retarding it.
\r\nX-ray fluorescence (XRF) and Raman spectroscopy are two complementary techniques suitable for the study of cultural heritage. XRF gives a quick highlight over the elements with a Z>12, allowing its identification and quantification whilst, Raman spectroscopy enables detailed information on the chemical compounds present in cultural heritage materials.
\r\nThe LIBPhys-UNL research group has been developing XRF setups with different characteristics according to the needs of each heritage object type. Triaxial geometry equipment presents a great advantage in the analysis of trace elements in low-Z matrix objects such as graphical documents. This geometry significantly reduces the background of the measured spectra by eliminating the Bremsstrahlung produced in the X-ray tube through crossed polarization in the secondary target and in the sample. In this way, a better peak-to-background ratio is obtained, improving the detection limits and leading to higher sensitivity. Combined portable XRF and Raman setups are mostly required for in-situ analysis of historical and artistic objects that are not allowed to leave the museums. In X-ray fluorescence spectrometry, the use of quantitative methods, independent of geometric and physical factors requires the use of standards of known composition, which should be as similar as possible to the unknown sample. The accuracy of this method depends on the number of standard samples used in the quantification and on the similarity of their composition with the unknown sample. A paper standards database consisting of well-known elemental composition paper samples is under construction enabling the elemental content determination of paper documents.
\r\nIn this talk, the most relevant work developed by the research group, concerning XRF setups development and quantitative methodologies and Raman combined applications to the study of graphical documents and other cultural heritage objects, will be presented.<\/div> \n \n DOWNLOAD DE ARQUIVO\n <\/a>\n <\/div>\n
Marta Cunha Monteiro Manso de Almeida Sampaio<\/i><\/b><\/h3>\n
Doutorada em F\u00edsica pela Faculdade de Ci\u00eancias da Universidade de Lisboa. Professora auxiliar convidada na FBAUL e Investigadora Integrada do LIBPhys-UNL. A sua investiga\u00e7\u00e3o incide na aplica\u00e7\u00e3o e desenvolvimento de m\u00e9todos anal\u00edticos de Fluoresc\u00eancia de Raios-X e Raman ao patrim\u00f3nio cultural, art\u00edstico e industrial procurando dar respostas a quest\u00f5es sobre tecnologia de produ\u00e7\u00e3o, conserva\u00e7\u00e3o preventiva e autenticidade. Conta com mais de 50 publica\u00e7\u00f5es em revistas de circula\u00e7\u00e3o internacional. Integra o comit\u00e9 cient\u00edfico do programa doutoral HERITAS da Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia (FCT). \u00c9 investigadora Principal de um projeto da FCT\/PT2020 \u201cCultura material, cultura cient\u00edfica: patrim\u00f3nio industrial para o futuro\u201d.<\/p>\n <\/div>\n <\/div>\n <\/div>\n<\/div>\n"}