Case study Physicochemical characterization
Transcrição
Case study Physicochemical characterization
Case Study: Physicochemical characterization of two 19th Century Portuguese Carte-de-Visite by non-destructive techniques M . P e r e s 1, L . D i a s 2, J . M i r ã o 2,3, T . F e r r e i r a 2,4, L . C a r v a l h o 5, F . C o s t a 1, E . J a r d i m 6 1C entro de Ciências Moleculares e Materiais, Universidade de Lisboa 2L aboratório HERCULES - Herança Cultural, Estudos e Salvaguarda, Universidade de Évora 3C entro de Geofísica de Évora, Universidade de Évora 4C entro de Química de Évora, Universidade de Évora 5C entro Física Atómica, Universidade de Lisboa 6C entro de Filosofia das Ciências, Universidade de Lisboa [email protected] 2nd International Workshop on Physical and Chemical Analytical Techniques in Cultural Heritage Lisbon, June 2012 SCIENTIFIC PHOTOGRAPHY: STUDY OF INSTRUMENTATION AND CHEMICAL-PHYSICAL PROCESSES DURING THE PERIOD 19TH- EARLY 20TH CENTURIES 2 R E S E A R C H P R O J E C T: P T D C / H I S - H C T/ 1 0 2 4 9 7 / 2 0 0 8 F I N A N C E D BY 3 4 MEMBERS • Fernanda Madalena Abreu Costa • Maria Estela de Freitas Vera - Cruz Jardim • Isabel Marília Viana e Peres • Marie Sophie Corcy • Pedro Miguel Barcia Ré • Rui Jorge Lourenço Santos Agostinho • Sara Raquel Dias de Sousa Carvalho • António Maria Reis Pereira 5 INTRODUCTION Identification of 19th century photographic prints Visual and microscopic methods of identification Identification of photographs using non contact and non destructive methods Qualitative and quantitative XRF analysis of photographs Scanning Electron Microscopy coupled with a Energy Dispersion Spectrometry (SEM-EDS) Reflectance Fourier-Transform Infrared Spectroscopy 19 th Century Portuguese Carte-de-Visite 6 Lady portrait (A. Solas) Man portrait (A. Solas) 7 EARLY PHOTOGRAPHIC Identification of primary visual clues : name PROCESS IDENTIFICATION METHODOLOGY of photographer, date, exhibition or photographic competition labels, logos, etc. Date: c. 1896 Identification of secondary visual clues: surface topography; tonality and colour of the image layer; presence or absence of fading or deterioration. (A. Solas, c. 1896) Glossy surface; brown tonality; no fading and some deterioration 8 IDENTIFICATION OF 19TH CENTURY PHOTOGRAPHIC PRINTS POSSIBLE STRUCTURE Protective layer Binder layer (image+ toning) Baryta layer Paper support Card (A. Solas; c.a. 1896) 9 Classification (Reilly; 1986) One layer (no binder layer and no baryta layer) Two Layers (no baryta layer) Three layers - Salted paper - Cyanotype - Platinotype - Albumen print - Carbon print - Gelatin silver (POP) - Collodion (POP) - Gelatin silver (DOP) 10 MICROSCOPIC EXAMINATION OF PHOTOGRAPHS Stereoscopic Zoom Microscope NIKON SMZ1500 • Magnification:10x and 70x • Illumination: 45º • Exposure and Gain: constants for each magnification C.C.M.M., Chemistry and Biochemistry Department, Faculty of Sciences, University of Lisbon (M. Peres, 2011) 11 MICROSCOPIC ANALYSIS Mag. 10x (200ms, 1,2x) Protective layer hide paper fibers Mag. 70x (600ms, 1,4x) 12 QUANTITATIVE X-RAY FLUORESCENCE SPECTROSCOPY (XRF) EDXRF Spectrometer • X-ray tube (PW 1140; 100 kV, 80 mA) equipped with a changeable secondary target, normally made off molybdenum • Si (Li) detector, with a 30 mm2 active area and 8 µm beryllium window • Energy resolution 135 eV at 5.9 keV and the acquisition system is a Nucleus PCA card • Commercial pulse processor (Oxford). • The X-ray generator was operated at 50 kV and 20 mA and a typical acquisition time of 1000 s was used Centro de Física Atómica, U.L. (M. Peres 2011) QUALITATIVE X-RAY FLUORESCENCE SPECTROSCOPY (XRF) 13 Pb Lβ 1 Pb Lα1 Pb L γ1 Pb L1 S Kα1 Ba Ba Kβ1 Kα2 Ba Lβ2,15 Pb η Sr Kα1 Ba Lγ1 Mn Kβ1 Ni Kα2 - No conclusive analysis regarding silver existence - Significant amount of lead - Possible presence of baryta layer Scanning Electron Microscopy coupled with Energy Dispersive Spectrometry (SEM-EDS) 14 The surface morphology and homogeneity of uncoated samples were analysed in a HITACHI S-3700N variable pressure Scanning Electron Microscope (SEM-EDS) coupled with a Bruker X-Ray Energy Dispersive Spectrometer used for elemental composition estimation. Acceleration voltage of 20.0 kV and variable pressure of 50 Pa were used for chemical analysis. Backscattered electron imaging mode was used. Laboratório HERCULES, Un. Évora (L. Dias, J. Mirão, T. Ferreira, 2011) 15 SEM-EDS ANALYSIS • Variable pressure chamber (50 Pa) • A 20 cm width chamber allows the analysis of the entire photograph avoiding microsampling Laboratório HERCULES, Un. Évora (L. Dias, J. Mirão, T. Ferreira, 2011) P5 P1 P3 P4 P2 P7 P6 SEM-EDS ANALYSIS 16 -Evidence of silver (no gold detected) -The significant amount of lead is confirmed and points out an enamelled paper -Overall presence of barium indicates a baryta layer Fourier-Transform Infrared Spectroscopy 17 • Fourier Transform Infrared Spectrometer ALPHA FTIR da BRUCKER OPTIKS , portable spectrometer • ALPHA model of Brücker with a reflectance module A241/DV QuickSnapTM and a video camera • 64 scans with 4 cm-1 resolution • Diameter of analysis: 6 mm • The spectra were obtained in the reflectance mode and converted to absorvance mode by the Kramers-Kronig algorithm. Laboratório HERCULES, Un. Évora Fourier-Transform Infrared Spectroscopy Comparative spectra analysis of A. Solas sample (G1) and mate collodion test sample (E2) Prova G1 Prova E2 (colódio mate) % T 18 2853 2922 1287 1643 3500 3000 2500 2000 1500 1004 856 1000 500 Nº de onda / cm-1 The IR spectrum comparison was done using the cellulose nitrate spectrum in transmittance from Getty Conservation Institute (DERRICK et al 1999). MULTI-TECHNIQUE NON-DESTRUCTIVE APPROACH 19 No gold Collodion Silver process c. 1896 Baryta layer ENNAMELED PAPER Lead Woodbury (1896) 20 FINAL NOTES • The microscopic essays using Reilly’s flowchart allowed us to do a first characterization of the analysed photographic prints. • Elemental analysis by non-invasive XRF and SEM-EDS provided additional information about photographic prints (presence of baryta layer, toning with gold, the presence of sulfur as a degradation agent) and knowledge about the surface morphology and homogeneity of the prints. • Reflectance Fourier-Transform Infrared Spectroscopy allowed the identification of a protein material as well as the chemical nature of the protective material layer. • The use of multi-technique non-destructive approach provided information about the stratigraphic structure of the photographic prints and also allowed the identification of the major elements present in the samples. On the overall, the analyses revealed key information about the deterioration status of the photographic prints that can be critical to its preservation and restoration, being also useful on the identification of fakes or reproductions References 21 CATTANEO, B., CHELAZZI, D., GIORGI, R., SERENA, T., MERLO; C., BAGLIONO, P. (2008), Physico- chemical characterization and conservation issues of photographs dated between 1890 and 1910, Journal of Cultural Heritage, 9, pp. 277-284. ENYEART, J., ANDERSON, A., PERRON. S., ROLLINS, D., & FERNANDO, Q. (1983). Non-destructive Elemental Analysis of Photographic Paper and Emulsions Spectroscopy, History of Photography, Vol. 7, Nº. 2, pp. 99 – 113. by X-ray Florescence RICCI, C. et al (2007), ATR-FTIR imaging of albumen photographic prints, Journal of Cultural Heritage, 8: 387-395. STULIK, D. & KAPLAN, A. (2010), An example of complex composite materials and processes: Photography in ARTIOLI, G. (coord), Scientific Methods and Cultural Heritage: An Introduction to the Application of Materials Science to Archaeometry and Conservation Science, Oxford, University Press, pp. 419-433. WOODBURY, W. (1896). Enamel paper. In The Encyclopaedic Dictionary of Photography. W. Woodbury. New York, The Scovill & Adams Company of New York, p. 192. 22 Acknowledgements: Acknowledgements • FCT- Fundação para a Ciência e Tecnologia • Ministério da Educação de Portugal • Anabela Boavida, C.C.M.M, Fac. de Ciências da Un. de Lisboa • José Carlos Frade, Laboratório de Conservação e Restauro José de Figueiredo, Instituto dos Museus e da Conservação. • Nuno Borges de Photography, Braga Araújo, Historian of
Documentos relacionados
délio jasse - Mariane Ibrahim
screens, although soon afterwards this led him to photography. He soon started experimenting with the different technical possibilities of this medium, especially the alternative processes such as ...
Leia mais