TOP STORY

Joe Deitzel:  Making Better Composites Through Polymer Science
By Diane Kukich

CCM Associate Scientist Joe Deitzel is a big guy who thinks small—when it comes to materials, that is.  He is involved with a variety of projects at CCM, most of which focus on nanoscale manipulation of material structure.

A polymer scientist by training, Deitzel holds a Ph.D. from the University of Akron.  He joined the research staff at CCM in 2001, after serving as a postdoctoral fellow at the U.S. Army Research Laboratory for four years.

Nanomaterials have attracted a great deal of attention for a broad range of applications in the past several years because of their unique properties.  Deitzel explains that nanofiber textiles have orders of magnitude greater specific surface area than conventional fabrics, due to the small fiber diameter.  “The greater surface area provides more interaction between the resin and reinforcing fiber, improving mechanical properties and potentially attenuating crack propagation,” he says.  In one current project, he and his research group are developing a novel approach to increasing the impact properties of thermoset and thermoplastic transparent polymer resins by reinforcing these resins with high-performance polymer nanofibers.


Joseph Deitzel
CCM Associate Scientist

Much of Deitzel’s work involves development and application of the electrospinning process, which yields uniform, nanometer-diameter polymer filaments.  “This process is a very effective method for making functionalized fabrics for protection against biological and chemical hazards,” Deitzel says.  “Nanofiber textiles enable us to incorporate a continuous network into a resin system, yielding tailored properties while also eliminating the problems associated with mixing and phase separation.  With these materials, we can use traditional composite processing techniques like RTM and VARTM without having to worry about dispersion, which is an issue with fillers and particulates.”

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SEM images of highly oriented polymeric and ceramic fibers made by electrospinning: (A) PVP fibers; (B) PMMA fiber; (C) PEO-TiO2 fiber; and (D) TiO2 nano-crystal fibers after heating at 500oC for 4 hours.

Deitzel and his research team are using the Center’s in-house multiple-jet electrospinning facility in their efforts to develop a better fundamental understanding of this process, which is a prerequisite to surmounting the technical barriers associated with scale-up and commercialization.  “That fundamental understanding,” Deitzel explains, “will lay the foundation for development of the computational and experimental tools needed to efficiently design, optimize, and scale-up the process for materials of interest.”

Deitzel is also developing methods to characterize high-performance organic fibers on the micro-scale.  “Our goal is to relate the molecular architecture to the microstructure to the macroscale properties,” he says.  He explains that his research group has developed a new technique for axial compression testing of new fibers such as M5 and Armos. 

“We’re trying to understand the role of hydrogen bonding in compression properties,” he says.  “Organic fibers have become suitable reinforcing materials for ballistic applications due to their outstanding specific tensile strength and energy absorption capabilities.  The development of new organic fibers with enhanced compressive properties will further expand the use of these lightweight materials to structural applications in fields such as aerospace, marine, automotive, and construction.”

Following on the foundation laid by the late Roy McCullough, Deitzel is also exploring the fiber-matrix interface in composites.  “We’re looking at adhesion issues in particular,” he says.  “One promising approach is the use of plasma treatment to improve bonding of high-performance thermoplastic composites such as PEEK and PEKK.  We’re also looking at controlling the texture of  glass fibers to improve ballistic properties for armor applications.”

Deitzel was drawn to CCM from his position as a postdoc at ARL.  “I began working with students on some of our collaborative projects,” he says, “and when the opening came up at CCM, I decided I was ready to return to academia.  “I’ve really enjoyed my time and have been offered great opportunities to explore issues of interest to me.  I also enjoy co-advising students.”

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Failure modes of M5 as spun and heat treated fiber specimens
under direct axial compression

OTHER NEWS

Commemorative Symposium In honor of
ARTHUR B. METZNER
The University of Delaware’s
H. Fletcher Brown Professor Emeritus of Chemical Engineering

Monday, May 14, 2007
John M. Clayton Hall

Invitation
Program and Registration Form
earthrace_image1
Arthur B. Metzner

Join us for a joint seminar sponsored by the Department of Mechanical Engineering and the Center for Composite Materials:
Dr. A.M. Rajendran, U.S. Army Research Office
“Research Opportunities in Engineering Sciences at the Army Research Office”
Friday, April 20, 2007, 11:00 A.M.
106 Center for Composite Materials
Details

Professor Richard Wool Named Recipient of the "Distinguished Paper Award" By Society of Adhesion.
The paper was presented at the Adhesion Society Annual Meeting , Tampa Florida Feb 18, 2007
The paper entitled: "Polymer-Solid Interface Connectivity and Adhesion: Design of a Bio-based Pressure Sensitive Adhesive" was co authored by Shana
Bunker, a PhD Graduate from Chemical Engineering, who now works for Dow Chemical.

UDaily Story
Delaware Researchers Part of Fuel Cell Team
10:50 a.m., March 27, 2007--University of Delaware scientists are part of a team headed by Nuvera Fuel Cells Inc. of Cambridge, Mass., that has won a $5 million U.S. Department of Energy grant for research and development of fuel cells.
Full Story in UDaily

 

CONSORTIUM

CCM would like to thank Protective Materials Company, Miami, FL, and Embraer, Sao Jose dos Campos, Brazil, for joining our consortium. We also wish to thank AMTECH Corporation, Yelm, WA, for the recent renewal of their membership.

To learn more about our Consortium, please visit http://www.ccm.udel.edu/Consortium/members.html .

consortium

PUBLICATIONS

Conference Proceedings

Thostenson, E. T., and T-W. Chou, "Multifunctional Composites with Self-Sensing Capabilities: Carbon Nanotube-Based Networks," SPIE Smart Structures and Materials & Nondestructive Evaluation and Health Monitoring (SS/NDE) 2007, Proceedings of SPIE Volume: 6526, San Diego, CA, March 18-22, 2007.

Invited Talks/Presentations

Thostenson E. T., "Nanostructured Composite Materials: Bridging the Micro and Nano Scales," IDGA Next Generation Materials for Defense 2007, Nanomaterials Focus Day,  Arlington, VA, March 27, 2007.

Journals

Gilhooley, D. F., R. C. Batra, J. R. Xiao, J. W. Gillespie Jr., and M.A. McCarthy, “Analysis of Thick Functionally Graded Plates by using Higher-Order Shear and Normal Deformable Plate Theory and MLPG Method with Radial Basis Functions,” Composite Structures, 80 (4), pp. 539-552, 2007.

Su, D., Santare, M. H., and Gazonas, G. A., “The Effect of Crack Face Contact on the Anisotropic Effective Moduli of Microcrack Damaged Media,” Engineering Fracture Mechanics, 74 (9), pp. 1436-55, 2007.


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