Silicone Rubber Research at the Metropolitan Museum of Art's Department of Scientific Research (DSR)
The eight silicone rubber molds investigated. Image: Anna Serotta
Residues remaining on stone slab after application of silicone rubbers. Image: Anna Serotta
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During the summer of 2011, I completed an internship in the Met's DSR working on a collaborative project with Adriana Rizzo and Anna Serotta investigating residues left behind by silicone rubber molds on porous surfaces. This research provided me with an introduction to conservation materials, working in a museum, and interdisciplinary research. I spent the summer in the lab running samples for analysis using FTIR and Py-GC/MS, preparing cross sections, and interpreting data. I really enjoyed the research, but found myself increasingly curious about the objects undergoing conservation treatment in the nearby lab. It would be another two years until my first direct conservation internship, but it was an incredibly formative moment in my career as it offered a first real glimpse into museum work.
I was fortunate to have the opportunity to travel to Albuquerque, NM to present this research at the Research and Technical Studies Session of AIC's Annual Meeting in 2012. At the bottom of this page, I have included a copy of the abstract submitted. |
Research Summary
Findings
- Eight different silicone rubbers were tested, including slow setting and long setting
- Bulk compositions were analyzed via pyrolysis gas chromatography mass spectrometry (Py-GC/MS), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), and evolved gas analysis (EGA)
- Residues left behind on glass slides were analyzed using FTIR, and residues absorbed into plaster of Paris sample coupons were prepared for in cross section and analyzed using ATR-FTIR to assess depth of penetration
Findings
- All silicone rubber molds tested left behind siloxane residues, to some degree
- The residues alter surface properties, including change in color as well as wettability
- Quick setting molds left less residue than long setting molds
- Siloxane residues may be reduced by cleaning with a non-polar solvent, but are unlikely to be fully removed
- Barrier layers should always be used in order to prevent the deposition of siloxane residues