Atomic Oxygen and Art Restoration

1. Atomic Oxygen and Art Restoration Molly Andreason April 28, 2005 Physics Seminar Presentation

2. Atomic Oxygen: Background • Present in Earth’s atmosphere at levels where satellites typically orbit • Treatment originally researched by NASA • Interested in effects of atomic oxygen interaction with materials

3. Carbon and Oxygen: • Charcoal and soot from fire damage essentially composed of carbon • Atomic oxygen readily oxidizes with surfaces or deposits containing carbon or hydrocarbon molecules • Carbon converted to volatile species • Mostly carbon monoxide C + O  CO • Some carbon dioxide CO + O  CO2 • Possible water vapor if C-H bonds in deposits

4. Why use atomic oxygen treatment? • Process is in gas phase  no mechanical contact • Reaction confined to surface  reduced risk of damaging underlying paint or canvas • Materials already in a high oxidation state (i.e. metal oxides used in many paints) typically unaffected by atomic oxygen • Is a dry process  no risk of leaching or swelling of painting

5. The Treatment Process • Oxygen molecules dissociated via radio frequency, microwave radiation, or electron bombardment • Done under partial vacuum  at 0.027-20 Pa, dependent upon the oxygen dissociation process used • Atoms at low energy either directed toward surface or allowed to surround object in closed chamber

6. An example: Monet’s “Water Lilies” • 1958: a museum fire severely damaged painting • Many conservation treatment techniques attempted—none shown to be effective as of December 2001 • Small chip removed from edge of painting for atomic oxygen treatment

7. Monitoring color changes and contrast • Measured diffuse reflectance from 450-650nm to monitor treatment progress • Compared changes in: • Surface of chip vs. shape of spectral curve • Color contrast vs. treatment time • End point of treatment indicated by: • No discernible difference in change in contrast values • Shape of diffuse reflectance vs. wavelength curve remaining stable over treatment time

8. Restoration Results a. Prior to treatment b. After atomic oxygen treatment c. After treatment and application of acrylic varnish

9. Some other examples: Duplicate of Raphael’s “Madonna of the Chair” by Bianchini. Damaged from an arson fire at a church in the 1980s, previously considered unsalvageable and was donated for testing atomic oxygen treatment

10. A painting of Mary Magdeline, heavily damaged from an arson fire at a church in 1989; painting was also severely blistered

11. Treatment seems to work for repairing other damages…. Atomic oxygen treatment also shown effective on removing other residues with organic components, such as graffiti, felt tip and ball point ink, and… …lipstick!

12. Conclusion: • Atomic oxygen has shown to be effective when applied to numerous media • One possible drawback: if paint binder is charred, treatment loosens some of the pigments  need to apply acrylic varnish post-treatment • Atomic oxygen treatment not intended to replace conventional techniques, but used as an additional conservation tool when traditional methods prove ineffective

13. Sources • Banks, B.A., et al. “Use of Atmospheric Oxygen Beam for Restoration of Defaced Paintings.” 1999. NASA TM-1999-209441. • Miller, S.K.R., et al. “Treatment and Analysis of a Paint Chip from ‘Water Lilies’ a Fire Damaged Monet.” 2001. NASA TM-2001-211326. • Miller, S.K.R., et al. “Atomic Oxygen and Its Effect on a Variety of Artist’s Media.” 2005. NASA TM-2005-213434. • Rutledge, S.K., et al. “Atomic Oxygen Treatment as a Method of Recovering Smoke Damaged Paintings.” 1998. NASA TM-1998-208507.