AIC 43rd Annual Meeting – The Daguerreotype Uncovered: An Overview of the Surface and Subsurface Chemistry, Physics and Material Science Underlying the First Photographic Process Based on Electron Microscopial Studies. Patrick Ravines

This presentation was delivered by Patrick Ravines, Director and Associate Professor, Buffalo State University. Co-authors include Peter Bush, Lisa Chan, Natasha Erdman, Lingjia Li, Rob McElroy, and Anne West.
Patrick et al have been using electron microscopy to investigate the surface and subsurface of daguerreotypes. They have created fresh plates for the investigation, and have used these analytical techniques during each stage of preparation. They have made discoveries including how scratches to the surface Ag are not always completely removed during the polishing process, polishing removes approximately 1 mm of Ag, and fuming with I2 creates a discontinuous layer of AgI across the plate. One interesting thing Patrick noted was how upon placing a sensitized daguerreotype plate in an SEM, the electron beam produced enough energy to cause the AgI particles to print out before their eyes. After exposure to Hg vapor, they were able to observe the Ag-Hg particles from various angles and discern that there are many other cluster shapes than cubic and hexagonal. Using lasers, they drilled into the daguerreotype surface, created cross-sections, and observed the subsurface voids. Patrick discussed their believe that the subsurface voids are the result of Ag migrating up to the surface to form the image material, leaving behind an absence of material. This work will be published soon in more detail.
Patrick noted that professionals in the electronics industry are using similar materials, Ag and Au, and they are finding similar subsurface voids.