Researchers in the Materials Science and Engineering (MATSE) Department at Penn State have published their work on the cover of the latest issue of ACS Macro Letters, a new journal in polymer science.
The research was performed by Shudipto Dishari, a postdoctoral scholar in the research group of Michael Hickner, assistant professor of materials science and engineering, and the Virginia S. and Philip L. Walker, Jr. Faculty Fellow. The journal cover art was designed by Dishari and Mike Fleck, multimedia specialist in MATSE. The paper describes a phenomenon called “antiplasticization” where a polymer film gets harder with the introduction of solvent. Dishari and Hickner found that very thin films of polymer antiplasticize, while thicker films show the expected behavior of plasticization or a softening of the polymer when solvent enters the film. In Dishari and Hickner’s work, Nafion, a popular polymer for fuel cells, stiffened when water was added to a 70-600 nanometer-thin film. Usually, Nafion with thicknesses of 25-150 microns (500-1000 times thicker than Hickner and Dishari’s thin films) becomes softer as it uptakes water.
The unexpected behavior of thin Nafion films in this work are important for the design and operation of hydrogen fuel cells, a next-generation technology for energy conversion and storage. The properties of the thin Nafion films studied in this work are virtually unknown. Hickner and Dishari are working with a team of scientists led by Jon Owejan at General Motors to discover new behaviors of these thin films where the dimensions of the material approach the size of molecules in the film. Fundamental understanding at this nanometer length scale will enable focused development for improving fuel cell performance and lowering their cost.
The work was funded under grant DE-EE0000470 by the U.S. Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy (EERE) through the Fuel Cells Technology Program. The research at Penn State is performed under subcontract with General Motors, the lead partner in the DOE project. Other project partners include Jack Brenizer at Penn State, Matthew Mench at the University of Tennessee Knoxville, and Satish Kandlikar and Thomas Trabold at Rochester Institute of Technology.
For more information, contact Hickner at mah49@psu.edu.
ACS Macro Letters was started this year by the American Chemical Society to rapidly publish new results that demonstrate fundamental advances to a wide range of researchers interested in macromolecular soft matter. ACS Macro Letters complements Macromolecules, the most cited journal in polymer science and offers full citation, including page numbers, when letters are first published to the Web. ACS Letters journals average four to six weeks from submission to Web publication.
For more information on ACS Macro Letters, visit http://pubs.acs.org/journal/amlcc.