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

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

3. Carbon and Oxygen: oCharcoal and soot from fire damage essentially composed of carbon oAtomic oxygen readily oxidizes with surfaces or deposits containing carbon or hydrocarbon molecules oCarbon converted to volatile species oMostly carbon monoxideC + O  CO oSome carbon dioxideCO + O  CO 2 oPossible water vapor if C-H bonds in deposits

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

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

6. An example: Monet’s “Water Lilies” o1958: a museum fire severely damaged painting oMany conservation treatment techniques attempted—none shown to be effective as of December 2001 oSmall chip removed from edge of painting for atomic oxygen treatment

7. Monitoring color changes and contrast oMeasured diffuse reflectance from 450- 650nm to monitor treatment progress oCompared changes in: oSurface of chip vs. shape of spectral curve oColor contrast vs. treatment time oEnd point of treatment indicated by: oNo discernible difference in change in contrast values oShape 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: oAtomic oxygen has shown to be effective when applied to numerous media oOne possible drawback: if paint binder is charred, treatment loosens some of the pigments  need to apply acrylic varnish post-treatment oAtomic 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.