NIST Tech Beat - August 27, 2003

Editor’s Note: With the July 9, 2003 issue, we combined under one title two NIST newsletters, NIST Update and NIST TechBeat. We’ve made the change to help improve the timeliness of our topics. Our goal is to include newsworthy topics tied to publication of peer-reviewed papers, conference presentations, and other timely “news hooks” as often as possible. We also will be including photos and graphics whenever possible.
We hope you like the new look! Please let me know if you have any comments or suggestions.

Recipe for a 'Shake Gel'

Chemists and computer scientists are using a special facility at the National Institute of Standards and Technology (NIST) to scale molecules up for people-sized interactions. Using chemical data, NIST software, special eyewear, and floor-to-ceiling display screens, they create giant three-dimensional molecules that move. Molecular behavior can be seen and understood in minutes instead of the weeks required using traditional techniques.

NIST scientists and collaborators used the 3D facility to study "smart gels," inexpensive materials that expand or contract in response to external stimuli. For example, a “smart” artificial pancreas might release insulin inside the body in response to high sugar levels. Other applications may include exotic foods, cosmetics or sensors. But scientists need to better understand the molecular behavior of the gels before they can optimize them for specific products.

The NIST team is studying a category of these materials called shake gels. Mixtures of clays and polymers, these materials firm up into gels when shaken, and then gradually relax again to liquids. In a shock absorber, for instance, such materials would generally be liquid but would stiffen into a gel when the car drove over bumps or potholes.

The visualization facility helped the scientists see that it is the polymer's oxygen atoms, not the hydrogen atoms as previously thought, that attach to the clay. The team's theoretical calculations also showed that water binds to the clay surfaces in a perpendicular arrangement. This may help create the firmness of the gel. Theoretical aspects of the smart gels research are discussed in the Aug. 28 issue of Journal of Physical Chemistry B. The work is sponsored by Kraft Foods and involves scientists from NIST, Los Alamos National Laboratory and Harvard University. (More detailed version of this article)

Detoxifying Sediments With Electrons and UV Light

The concentration of certain toxic organic chemicals in waterway sediments can be reduced by 83 percent using electron beams--the same technology already used to decontaminate mail--scientists from the National Institute of Standards and Technology (NIST) and the University of Maryland will report in the Sept. 1 issue of Environmental Science & Technology. In an additional series of laboratory experiments, the team found that ultraviolet light also can substantially reduce the concentration of these chemicals.

The results are significant because sediments, soupy mixtures of water and particles of various sizes, are notoriously difficult and expensive to decontaminate. Further, electron beams and ultraviolet light effectively detoxified the banned chemicals known collectively as polychlorinated biphenyls, or PCBs, which can get into the food chain and increase the risk of cancer in humans. Waterways such as the Hudson River have bottom sediments heavily contaminated with PCBs. However, whether electron beams and ultraviolet light are practical decontamination techniques will depend on cost-effectiveness comparisons to existing methods, such as chemical treatment and incineration. In addition, issues such as availability of electron beams will need to be resolved. The scientists used a beam at the University of Maryland for the recent studies.

Electron beams and ultraviolet light remove chlorine ions (charged atoms) from PCBs, which reduces toxicity and enhances prospects for biodegradation of the remaining material by living organisms. The scientists evaluated the effectiveness of the treatment methods in removing PCBs from a NIST Standard Reference Material containing sediments with carefully measured amounts of contaminants. Research continues on additives and conditions that might enhance the decontamination processes. The research is funded by NIST, the university, and the Maryland Water Resources Center.

Media Contact:
Laura Ost, (301) 975-4034

MEP Center Helps Maine Company Build Bright Future on the Past

If you have been in a craft or hobby store lately, you know that "scrapbooking" has gone way beyond pasting a few vacation photos and a napkin from that great restaurant in an album. Today, scrapbookers create family memory albums using photographs, journal entries and lots of decorative accessories. The Hobby Industry Association estimates that more than 13 million people in the United States spent more than $2 billion on this hobby in 2002.

Archival Solutions, a small, woman-owned business in Raymond, Maine, was having great success selling their scrapbooking products. But co-owners Christine Sutton and Tracey DuBois wanted to expand by designing a new line of products that were acid free and met all the Library of Congress criteria for archival products. The women turned to the Maine Manufacturing Extension Partnership, an affiliate of the nationwide National Institute of Standards and Technology (NIST) Manufacturing Extension Partnership (MEP), for assistance in getting a $10,000 grant; in identifying technically advanced acid-free materials; and in constructing product prototypes. The Maine MEP also called on paper and plastics experts at the University of Maine to perform product testing and validation.

Sutton and DuBois recently introduced their new product line to great reviews at the Hobby Industry Association International Show. As a result of the assistance they received from Maine MEP, the company retained two position--there are now four employees--and sales are projected to increase from $5,000 a year to $100,000. “This provides our company with a significant competitive advantage and positions us for growth and financial success,” said Sutton.

For more information on the Maine MEP, call (207) 623-0680. The NIST MEP is a nationwide network of manufacturing extension centers and field offices providing a wide variety of expertise and services to small manufacturers in all 50 states and Puerto Rico. More information can be found at www.mep.nist.gov or manufacturers can reach the center serving their area by calling (800) MEP-4MFG (637-4634).

With Neutrons, Partners Pursue The Scent of Success

Get a whiff of this! A new research partnership at the National Institute of Standards and Technology (NIST) is using beams of chilled neutrons to determine how aroma compounds are embedded into assortments of other chemicals that carry and release fragrances in perfumes, detergents and other scented products.

Securing the elusive structural details could lead to what might be termed an "odor of magnitude" improvement in models for predicting interactions between fragrances and their molecular carriers. The cooperative project involves researchers from International Flavors & Fragrances (IFF), based in New York City, and NIST.

Besides contributing in other ways to product performance, carrier molecules band together and enwrap fragrance ingredients. IFF Associate Research Fellow Chii-Fen Wang likens the structural arrangement to an onion. "We want to determine where the fragrance compound is located in the onion--in the center, for example, or in a particular layer--and how the structure of the compound changes," she explains.

Detecting how neutrons are scattered as they pass through a sample reveals the locations and shapes of fragrance and carrier molecules over time, information of great interest to Wang and her IFF colleague, Johan Pluyter. The cold (slowed-down) neutrons available at the NIST Center for Neutron Research are ideal probes, says NIST team member Steven Kline. These chilled subatomic particles have wavelengths that will enable the team to measure the structural details that it seeks, which are on the order of 1 nanometer to
100 nanometers.

This basic information, says Wang, can guide efforts to enhance models for formulating carriers that are optimized for specific fragrances and products. With more accurate models, fragrance chemists can, for example, sidestep undesired molecular changes that subvert a desired aroma.

NIST, Partners with Team to Improve Building Regulatory Systems—NIST is providing financial and technical support of the "Building Regulatory Process Streamlining Project" effort coordinated by the National Alliance for Building Regulatory Reform in the Digital Age. The seven-month initiative will facilitate the effective use of interoperable information technology systems, software and standards to modernize state and local building and fire safety regulatory systems. For more information, go to www.ncsbcs.org. Click on the National Alliance for Building Regulatory Reform in the Digital Age and scroll down to the press release on the project.

New IT Security Guide Available—NIST has released its final version of guidelines for developing metrics to help ensure that federal agencies meet information technology security program requirements. The guide can be adapted by private-sector organizations to meet their own needs. NIST Special Publication 800-55, Security Metrics Guide for IT Systems is available at http://csrc.nist.gov/publications/nistpubs/800-55/sp800-55.pdf

NIST, University of Maryland Expand Collaborations—NIST and the University of Maryland recently signed two agreements to broadly expand research collaborations and professional linkages between the two institutions. In particular, one of the agreements calls for both organizations to work together in the areas of nanometrology, nanomanufacturing and related areas. Copies of the agreements are available at www.nist.gov/public_affairs/newsfromnist_umdmou.htm.