Materials Scientists, Conservators Join Forces to Preserve Silver Artifacts and Art

COLLEGE PARK, Md., Oct. 26 /PRNewswire-USNewswire/ -- Where there's silver, there's tarnish. While getting the tarnish off your flatware might be an occasional inconvenience, to museum curators and conservators, it's a threat to irreplaceable works of art.

To protect these objects for generations to come, scientists from the A. James Clark School of Engineering at the University of Maryland, College Park, have teamed up with conservators from the Walters Art Museum in Baltimore, Md., to develop and test a new, high-tech way to protect silver art objects and artifacts, using coatings that are mere nanometers thick.

The technique, called atomic layer deposition (ALD), will be used to create nanometer-thick, metal oxide films which, when applied to an artifact, are both transparent and optimized to reduce the rate of silver corrosion. The films are created when an object is exposed to two or more gases that react with its surface.

"ALD gives us an exquisite level of control, literally at the atomic level," says Ray Phaneuf, a professor of materials science and engineering (MSE) working on the project. "It's an effective, low-cost strategy to reduce corrosion that preserves artifact appearance and composition while complying with the rigorous standards of art conservation practice."

Eric Breitung, a scientist who runs E-squared Art Conservation Science, proposed the collaboration after conducting preliminary investigations into the use of ALD on silver at New York's Metropolitan Museum of Art.

"I approached members of the Clark School faculty because of their expertise and the university's extensive ALD facilities at the Maryland NanoCenter," he says, adding that the faculty members' previous collaborations with museums made them a good match for the Walters and its silver collection.

Walters Art Museum Conservation Scientist Glenn Gates explains the goals the new coating has to achieve.

"First, its appearance must be acceptable for display in a museum context.  It has to be tough enough to endure transport and handling, but not so tough that it can't be removed. It needs to be completely removable so an object can be re-treated to meet future standards of conservation and aesthetics. And finally, it should not cause any harm to a piece, even if it breaks down."

Gates, who works with the Walters' world-class silver collection, is well acquainted with the battle against tarnish. He points out the project's figurative mascot, Antoine Louis Barye's 1865 "Walking Lion" sculpture, as exactly the sort of piece that could one day benefit from the new treatment. It has been cleaned and lacquered twice since 1949, but in both cases ultimately experienced deterioration problems with its coatings. It is currently unlacquered but must be kept in a special exhibition case to ward off tarnish.

"The 'Walking Lion' represents a complex shape that, being difficult to coat with traditional lacquer, might benefit from ALD protection," he says.

The team will test the new technique, first on small samples of fine and sterling silver, and then on objects from Gates' own collection, such as 19th century demitasse spoons and Morgan silver dollars. While the Walters does not expect any pieces from its collection to receive the experimental treatment during the course of the study, once it has been proven effective and safe, the "Walking Lion" would be a prime candidate for this procedure.

The three-year project is one of the first to be funded by the National Science Foundation's Chemistry and Materials Research at the Interface between Science and Art (SCIART) grant program, which supports projects in the field of cultural heritage science through the funding of collaborations among conservation experts in museums and scientists in academia. The SCIART program will be highlighted at the 2011 national meeting of the American Chemical Society, which has invited the team to present their work. 

The project's other team members include the museum's Director of Conservation and Technical Research Terry Drayman-Weisser, a recognized metals expert, and, from the University of Maryland's Department of Materials Science and Engineering, Professor Gary Rubloff, Research Associate Laurent Henn-Lecordier, and Graduate Assistant Amy Marquardt, who brings to the project her previous experience working on bronze patinas with the Smithsonian's Museum Conservation Institute.

NOTE TO EDITORS: A hi-res photo of the "Walking Lion" sculpture is available with the online version of this release here: http://www.eng.umd.edu/media/release.php?id=63.

For More Information:

Visit the Department of Materials Science and Engineering web site: http://www.mse.umd.edu

Visit the Walters Art Museum web site: http://thewalters.org/

Visit the Maryland NanoCenter web site: http://nanocenter.umd.edu  

Visit the NSF SCIART grant homepage: http://www.nsf.gov/pubs/2010/nsf10534/nsf10534.htm

About the A. James Clark School of Engineering

The Clark School of Engineering, situated on the rolling, 1,500-acre University of Maryland campus in College Park, Md., is one of the premier engineering schools in the U.S., with graduate and undergraduate education programs ranked in or near the Top 20. In 2010, the Clark School was ranked 13th in the world by the Institute of Higher Education and Center for World-Class Universities in its Academic Ranking of World Universities. Three faculty members affiliated with the Clark School were inducted into the National Academy of Engineering in 2010.

The school, which offers 13 graduate programs and 12 undergraduate programs, including degree and certification programs tailored for working professionals, is home to one of the most vibrant research programs in the country. The Clark School garnered research awards of $171 million in the last year. With emphasis in key areas such as energy, nanotechnology and materials, bioengineering, robotics, communications and networking, life cycle and reliability engineering, project management, intelligent transportation systems and aerospace, the Clark School is leading the way toward the next generations of engineering advances.

Visit the Clark School homepage at www.eng.umd.edu.  

About the Walters Art Museum

The Walters Art Museum is located in downtown Baltimore's historic Mount Vernon Cultural District at North Charles and Centre streets and is one of only a few museums worldwide to present a comprehensive history of art from the third millennium B.C. to the early 20th century. Collection highlights include Egyptian mummies, Renaissance suits of armor, Faberge eggs, Art Nouveau jewelry and old master paintings. Among its thousands of treasures, the Walters holds the finest collection of ivories, jewelry, enamels and bronzes in America and a spectacular reserve of illuminated manuscripts and rare books. The Walters' Egyptian, Greek and Roman, Byzantine, Ethiopian and western medieval art collections are among the best in the nation, as are the museum's holdings of Renaissance and Asian art. Every major trend in French painting during the 19th century is represented by one or more works in the Walters' collection.

Visit the Walters homepage at www.thewalters.org.

SOURCE A. James Clark School of Engineering