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Ronald Hedden
Assistant Professor of Materials Science and Engineering
325C Steidle Building
814-863-2325
hedden@matse.psu.edu |
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Biographical Sketch:
Professor Hedden received his B.S. degree in Chemical Engineering
from Penn State in 1995, where his undergraduate research with
Dr. Larry Duda fostered interest in polymer science and engineering.
Dr. Hedden attended graduate school at Cornell University, where
he studied liquid crystalline polymers and networks with Prof.
Claude Cohen in Chemical Engineering, earning his Ph. D. in 2000.
After receiving a National Research Council postdoctoral fellowship,
Dr. Hedden studied with Dr. Barry Bauer at the National Institute
of Standards and Technology in Gaithersburg, MD from 2000-2003,
broadening his materials interests to encompass dendrimers and
low-dielectric constant thin films. In 2003, he joined the faculty
at Penn State as an Assistant Professor of Materials Science
and Engineering and member of the Materials Research Institute.
Dr. Hedden's group is currently focused on polymer physics research,
with emphasis on networks, gels, and elastomers. Developing interests
include thin polymer films, and soft materials for biomass energy
applications. |
Research
Interests:
• Liquid
crystalline polymers and networks
• Polymer-based electrolytes for batteries and fuel
cells
• Dendrimers, dendrimer-gels, and dendrimer-star polymers
• Biohydrogen, biofuels, and bioreactor design
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Areas
of research:
Dr. Hedden's group has two primary materials research thrusts:
synthesis and characterization of polymer networks and gels,
and development/characterization of polymers for microelectronics
applications. In a typical research project, we synthesize
well-defined "model" polymers and characterize their physical
and engineering properties to better understand how molecular
architecture and nanometer-scale structure impact macroscopic
properties. In the "polymer networks and gels" area, we
are exploring liquid crystalline elastomers (LCE) (that may be
useful as artificial muscle tissue) (Fig. 1), hydrogels containing
dendrimers (which could have applications as tissue engineering
scaffolds), and lithium ion transport in polymer gel electrolytes
(for lithium ion batteries). In the area of "polymers
for microelectronic applications," we are studying novel photoresist
materials and methods for nanolithography at the 30 nm node. In
addition, we conduct experimental characterization of nanoporous
low-dielectric constant (low-k) thin films by neutron and x‑ray
methods. Characterization techniques used by our group
include dynamic mechanical analysis, optical birefringence microscopy,
FTIR spectroscopy, solid-state NMR spectroscopy, neutron scattering
(using facilities at the NIST Center for Neutron Research), broadband
dielectric spectrometry, x-ray diffraction, and x-ray reflectivity. Although
polymer synthesis plays an important role in most of our projects,
our work is aimed at fundamental advances in polymer physics
rather than the study of synthetic methods. Our research
projects also aim to discover advanced materials with exceptional
properties through the key insights gained from polymer physics
research. |
Technologies
impacted by research:
• Lithium
ion batteries
• Biomass energy
• Microelectronics
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Journal
Articles and Publications:
1. R.C. Hedden, H.-J. Lee, C.L. Soles, and B.J. Bauer, "Characterization
of Pore Structure in a Nanoporous Low-Dielectric-Constant Thin
Film by Neutron Porosimetry and X-ray Porosimetry." Langmuir
2004, 20(16), 6658-6667.
2. R.C. Hedden and B.J. Bauer, "Structure and Dimensions
of PAMAM/PEG Dendrimer-Star Polymers." Macromolecules
2003, 36(6), 1829-1835.
3. R.C. Hedden, B.J. Bauer, A.P. Smith,
F. Groehn, and E.J. Amis, "Templating
of Inorganic Nanoparticles by PAMAM/PEG Dendrimer-Star Polymers." Polymer
2002, 43, 5473-5481.
4. R.C. Hedden, H. Saxena, and C. Cohen, "Mechanical
Properties and Swelling Behavior of Endlinked Poly(diethylsiloxane)
Networks." Macromolecules
2000, 33, 8676-8684.
5. R.C. Hedden, H. Tachibana, T.M. Duncan,
and C. Cohen, “Effects of Molecular Structure on .Segment
Orientation in Poly(diethylsiloxane) Elastomers. 2. NMR Measurements
from Uniaxially Stretched Samples."
Macromolecules 2001, 34, 5540-5546.
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