Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nanotechnology Helps Scientists Keep Silver Shiny

30.10.2012
There are thousands of silver artifacts in museum collections around the world, and keeping them shiny is a constant challenge. So scientists are using new technology to give conservators a helping hand.

A team of researchers led by Ray Phaneuf, a professor of materials science and engineering at the University of Maryland, College Park, has partnered with The Walters Art Museum in Baltimore to investigate less labor-intensive ways to protect silver artifacts from tarnishing.

The new techniques, which might keep silver surfaces shiny for longer than traditional methods, could help ensure that historically important artifacts are preserved for future generations to learn from and enjoy. The researchers will present their work at the AVS 59th International Symposium and Exhibition, held Oct. 28 – Nov. 2, in Tampa, Fla.

Silver tarnishes when hydrogen sulfide in the air reacts with the silver, forming an unsightly black layer of silver sulfide on the surface of the artifact. If the tarnish appears on Grandma's silver flatware set, a little polisher and some elbow grease will easily remove it. But polishing, which works by dissolving or grinding away the silver-sulfide layer, can also remove some of the underlying silver, an undesirable outcome for priceless works of art.

Currently museum conservators can apply a thin layer of nitrocellulose lacquer to protect the silver. The coating is often hand-painted by a trained specialist and must be removed and reapplied an average of every thirty years. Phaneuf notes that it is difficult to apply a layer of even thickness over an entire piece, and the process of applying, removing, and reapplying the film is time-consuming.

"We did a quick back-of-the envelope calculation and found that for a big museum like the Metropolitan Museum of Art in New York, treating their entire silver collection with nitrocellulose films would likely be a never-ending task," says Phaneuf.

A quicker conservation method is to display silver pieces in an enclosed chamber with filtered air, but the chambers often leak, are expensive to install and maintain, and putting an artifact behind glass may prevent visitors from seeing the object up-close and from multiple angles.

Phaneuf and his colleagues are investigating a technique that could overcome some of the shortcomings of current preservation methods. Called atomic layer deposition (ALD), the process gives scientists atomic-level control over the thickness of a transparent oxide film that they grow on the surface of silver objects. By running a series of surface-limited chemical reactions, researchers can build the protective film one atom-thick layer at a time. The films Phaneuf and his team have tested are under 100 nanometers thick, less than 1/1000th the thickness of a human hair.

Phaneuf and his colleagues are currently experimenting by applying ALD films to highly uniform silver test wafers. The uniformity of the wafers allows the researchers to control variables, such as the composition of the silver, in order to create a model of the tarnishing kinetics as sulfur diffuses through the ALD film.

"This is when we get to put on our physicists' hats," Phaneuf says of simplifying the test cases and building a predictive model. The test case results showed two components to the concentration profile, indicating a faster rate of sulfur diffusion through tiny pinholes in the protective oxide film. The researchers are now experimenting with multilayer films that plug these pinholes.

Before the researchers use ALD on prized museum pieces, they will need to demonstrate that the coating can be removed without damaging the artifact, and that the thin film will have a minimal effect on the aesthetic look of the silver. In terms of appearance, ALD films may have another advantage over conventional nitrocellulose lacquer, which can yellow with age. Phaneuf and his colleagues are performing tests to measure how the thickness of the ALD films affects the way silver reflects light.

"Untreated silver beautifully reflects white light," Phaneuf explains. "You don't want the protective film to create interference effects that make it look blue or yellow." The expert eyes of art conservators will also help the researchers judge their success in this respect.

Phaneuf says that collaborating museums may soon allow the team to test their methods on forgeries of silver artifacts, and by year's end the team should be working with genuine pieces. "There is no shortage of complex objects this method might be applied to," Phaneuf notes. "There is a lot of interest now in the conservation community in how nanotechnology and other high technologies can be used to preserve art."

MORE INFORMATION ABOUT THE AVS 59th INTERNATIONAL SYMPOSIUM & EXHIBITION
The Tampa Convention Center is located along the Riverwalk in the heart of downtown Tampa at 333 S. Franklin St., Tampa, Florida, 33602.
USEFUL LINKS:
Main meeting website:
http://www2.avs.org/symposium/AVS59/pages/greetings.html
Technical Program:
http://www.avssymposium.org/
Housing and Travel Information:
http://www2.avs.org/symposium/AVS59/pages/housing_travel.html
PRESS REGISTRATION
The AVS Pressroom will be located in the Tampa Convention Center. Your complimentary media badge will allow you to utilize the pressroom to write, interview, collect new product releases, review material, or just relax. The media badge will also admit you, free of charge, into the exhibit area, lectures, and technical sessions, as well as the Welcome Mixer on Monday evening and the Awards Ceremony and Reception on Wednesday night. Pressroom hours are Monday-Thursday, 8-5 p.m.
To register, please contact:
Della Miller, AVS
E-mail: della@avs.org
This news release was prepared for AVS by the American Institute of Physics (AIP).
ABOUT AVS
Founded in 1953, AVS is a not-for-profit professional society that promotes communication between academia, government laboratories, and industry for the purpose of sharing research and development findings over a broad range of technologically relevant topics. Its symposia and journals provide an important forum for the dissemination of information in many areas of science and technology, enabling a critical gateway for the rapid insertion of scientific breakthroughs into manufacturing realities.
Della Miller
AVS
Phone: 530-896-0477
Email: della@avs.org
Catherine Meyers
AIP
Phone: 301-209-3088
Email: cmeyers@aip.org

Della Miller | EurekAlert!
Further information:
http://www.avs.org

More articles from Materials Sciences:

nachricht New biomaterial could replace plastic laminates, greatly reduce pollution
21.09.2017 | Penn State

nachricht Stopping problem ice -- by cracking it
21.09.2017 | Norwegian University of Science and Technology

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>