James Runt is currently Professor of Polymer Science in the MatSE Department at Penn State. Dr. Runt is the author of >210 peer-reviewed publications and book chapters, as well as co-inventor on 5 recent issued patents on a cardiac support device. He is a Fellow of the American Physical Society and the American Institute of Medical and Biological Engineers. He was a co-editor of a recent ACS Symposium Series book: Polymers for Energy Storage and Delivery: Polyelectrolytes for Batteries and Fuel Cells and an editor of the ACS Professional Reference Series book: Dielectric Spectroscopy of Polymeric Materials: Fundamentals and Applications. Dr. Runt serves on the Board of Directors of the International Dielectrics Society and has previously served on the Editorial Advisory Board of the journal Macromolecules. He received his Ph.D. degree from Penn State in Solid State Science, with a concentration in polymeric materials.
In general, our research focuses on the relationship between polymer dynamics and nanoscale phase separation, and how these influence macroscopic properties and performance of multiphase polymer systems.
Many important devices in the expanding energy sector require materials that conduct ions through a medium, including actuators and batteries. For many next generation devices, single-ion polymer conductors (ionomers) are preferred for the creation of solid ion transport membranes. Together with MatSE colleague Ralph Colby, we use dielectric (impedance) spectroscopy to develop molecular level understanding of ion transport and associated polymer dynamics in ionomers with various chemical structures.
In related research, we also use dielectric spectroscopy to interrogate ion and polymer dynamics in a remarkable new class of highly regular acid-functionalized (and cation-neutralized) ethylene copolymers. Both acid and/or ionic functionalities segregate from the polyethylene matrix and lead to unique morphologies.
For many years we have explored the role of hard and soft segment chemistries on nanodomain phase separated morphology, unlike segment demixing, and polymer dynamics in polyurethane segmented block copolymers and chemically related polyureas. The microstructural aspects of this work include the use of quantitative small-angle X-ray scattering and tapping mode AFM. Polyurethane chemistries under consideration have been chosen to reflect those of interest as blood-contacting materials in biomedical devices. Polyurea chemistries have been chosen to reflect those of interest for protection against shock impact loading (and protection against traumatic brain injury).
Finally, we are also investigating the fundamental connection between semi-crystalline polymer composition, molecular orientation, the resulting morphology, and their dielectric properties (from the point of view of film capacitor applications). The latter include, among others, dielectric constant and loss as well as breakdown strength.