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Christopher Soles to participate in NAE Frontiers of Engineering
Dr. Christopher Soles was invited and selected to participate in the National Academy of Engineering’s Tenth Annual Symposium on Frontiers of Engineering. The symposium will be help at the National Academies’ Arnold and Mabel Beckman Center in Irvine, CA September 9-11, 2004. The NAE Frontiers of Engineering program gathers outstanding leaders, generally between the ages of 30 and 45, from disparate fields of science and engineering and challenges them to think about the development at the frontiers of areas different from their own field. It is hoped that interactions lead to a variety of results, including collaborative work, transfer of techniques and approaches across fields, and the establishment of contacts among the next generation of engineering leaders. This year’s program will address Engineering for Extreme Environments, Designer Materials, Multi-scale Modeling, and Engineering and Entertainment.
MSEL Hosts the NIST Combinatorial Methods Center’s Fifth Industrial Workshop on Processing and Characterization
On April 26-27 2004, MSEL hosted the NIST Combinatorial Methods Center’s (NCMC) fifth workshop: Processing and Characterization. Over 40 representatives from the 24 NCMC partner institutions (see NCMC website at www.nist.gov/combi) attended. NIST staff, primarily from MSEL, BFRL and CSTL, also participated in the Workshop.
The goal of the workshop was to present a survey of combinatorial and high-throughput (“combi”) materials research capabilities across NIST and to identify routes for effective technology transfer to industry. Workshop activities included: a symposium outlining combi measurement methods developed at NIST (MSEL, BFRL, and CSTL), in particular techniques for the fabrication, processing, and characterization of multivariate specimen libraries; plenary talks from nScrypt, the Naval Research Laboratory and GE Global Research; discussions outlining proposed NCMC “Focus Projects”, aimed at direct technology transfer to industrial partners; a brainstorming session identifying industry needs in the acquisition and development of NCMC-generated gradient technologies; and tours and technical demonstrations of the NCMC core laboratory facilities in MSEL’s Polymers Division.
This is the latest in the biannual workshop series organized by the NCMC as part of its outreach to its partner institutions. The next workshop will be held in November 2004.
For more information on the NIST Combinatorial Methods Center, please visit the Center website at www.nist.gov/combi
CONTACT: Cher Davis, ext. 6488
Michael Fasolka, ext. 8526
MSEL Researchers Use Frustrated Optical Technique to Measure Formation of Nano-Coatings
Additives are frequently mixed into polymeric materials in minute quantities in order to make them processable into the typical products
well known to consumers, such as plastic sheets, pipes, and wire insulation.
However, the reasons behind the effectiveness of these additives had
remained mysterious because the existing tools available to measure
their behavior in the manufacturing process were rather crude. Now,
researchers in MSEL's Polymers Division have utilized the optical
phenomena of Frustrated Total Internal Reflection to directly visualize
the behavior of fluoropolymer additives when added to polyethylene.
The researchers discovered a continuous
process in which the fluoropolymer droplets "rain down"
on the internal surfaces of the extruder and form a nano-coating.
Similar to the fashion in which a fluoropolymer coated frying pan
prevents eggs from sticking, this nano-coating allows the polyethylene
to smoothly slide through the processing equipment with lower energy
utilization and without defects. Based on the measured thickness of
the coating, which ranges from 20 to 400 nanometers, a qualitative
model of this process was developed and published in the current issue
of Journal of Rheology. A collaboration between NIST, DuPont Dow Elastomers,
The University of Minnesota, and The University of Maryland is currently
using this technique to uncover the critical factors influencing the
coating efficiency.
For further information please
visit the Polymers Division webpage at www.nist.gov/polymers and search
Polymers webspace for "frustrated" or read the article in
the Journal of Rheology (vol. 47, no. 6, pp. 1523-1545).
MSEL researchers have established a versatile methodology to prepare
hybrid biomaterials by atom transfer radical polymerization (ATRP)
from resin-supported peptides. By incorporating cell-signaling moieties
in materials with defined molecular architecture, we can control the
interactions between polymeric materials and biological systems. Control
of such interactions is important not only for developing new biomaterials
but also for developing new metrologies for characterizing cell/material
interactions. ATRP was chosen to meet these needs because it allows
the synthesis of polymers with well-controlled molecular mass and
molecular mass distribution and is tolerant of many functional groups,
thereby permitting the controlled synthesis of a broad range of polymers.
Cell adhesion is a critical parameter
in biomaterials development because it is necessary for cells to produce
new tissue, cartilage, or bone, on tissue engineered scaffold materials.
In a proof of concept experiment, Polymers Division researchers used
ATRP to functionalize a polymer with poor cellular adhesion, with
a peptide sequence that has been shown to be important for binding
of a protein to cells. Poly(HEMA), or poly(2-hydroxyethyl methacrylate),
was chosen because it is one of the most extensively studied biocompatible,
hydrogel-forming polymers, that resists protein and cell adhesion.
GRGDS, which corresponds to the amino acid sequence: glycine-arginine-glycine-aspartic
acid-serine, was chosen because it has been identified as an important
sequence in binding of the protein fibronectin to membrane receptors
on cells.
As was expected, negligible cell
attachment was observed on the pure poly(HEMA) film after 24 h cell
culture. In contrast, cell attachment and spreading was found on the
GRGDS functionalized-poly(HEMA) film under identical conditions. This
research demonstrates that this methodology has the potential for
the control of cell-material interactions, and it will provide the
basis for new metrology development for characterizing the response
of biological systems to materials.
This research has been accepted
for publication in a forthcoming issue of the Journal of the American
Chemical Society.
Polymers Division researchers have successfully developed a broadband
standard test method for embedded passive devices as replacements
for discrete electrical components on printed circuit boards to advance
device miniaturization efforts. The test method enables accurate dielectric
measurements at previously inaccessible microwave frequencies for
high dielectric constant polymer composite materials needed for these
advanced electronics applications. The technique was developed within
a NIST chaired IPC standard test sub-committee chaired including a
number of industry representatives. The metrology was developed from
the observation and theoretical analysis of fundamental mode propagation
at high frequencies in thin film dielectrics terminating a coaxial
air-filled transmission line. Recently, 3D numerical simulations of
the electromagnetic field enabled an extension of the measurement
frequency limit from 5 GHz to 12 GHz.
The IPC committee forum has recognized
NIST for its leading role in the characterization of high-k composite
materials and for effectively addressing the standardization needs
of emerging electronic packaging technologies. These broadband dielectric
measurements for high-k composite materials have applications in biotechnology,
nanotechnology, and microelectronics.
For additional information on
this metrology, please visit the Polymers Division website at www.nist.gov/polymers
and search Division webspace for "microwave."
