Next Generation Energy Storage
Percolated Network Structures for Advanced Fuel Cells
We synthesized a precision proton conducting polymer through the sulfonation of hydrogenated poly(4-phenylcyclopentene). These unique materials place a highly polar phenylsulfonic acid group at precisely every 5th carbon along a flexible and highly non-polar all-hydrocarbon backbone. In collaboration with Prof. Karen Winey (UPenn) and Dr. Amalie Frischknecht (Sandia National Lab), it was determined the these systems self-assemble into percolated network structures with bicontinous channels of the polar acid regions. Upon hydration, these materials conduct protons better than Nafion-117, the current benchmark material in fuel cell technologies.
Utilization of Poly(vinylpyridine) Segments to Create Charge Mosaics
Diblock copolymers comprised of poly(4-vinylpyridine) (P4VP) and poly(tert-butyl methacrylate) (PtBMA) segments were self-assembled in the thin film state to produce perpendicular hexagonally packed cylinders of P4VP in a PtBMA matrix. The films were subsequently treated with bromoethane vapor to quaternize the P4VP domains followed by treatment of the films with HCl vapor to partially hydrolyze the PtBMA domains into poly(acrylic acid). After a final neutralization step, the resulting thin films retained their nanostructure domains that were each comprised of an oppositely charged polymer. In collaboration with Prof. Rafael Verduzco (Rice U.), time-of-flight secondary ion mass spectrometry (TOF-SIMS) was used to identify the presence and location of specific anions and cations within the microphase separated films. This work serves as a promising proof-of-concept for the use of P4VP and PtBMA segments towards the creation of charge mosaic membranes.
Unraveling Miscibility in SIC-Polyelectrolyte Blends for Improved Li-ion Batteries
Blending of single-ion conducting (SIC) polymers with polyelectrolytes (such as PEO) to facilitate high conduction of Li-ions with low transference is a potential method for safer and more stable next-gen Li-ion Batteries. However, predicting the miscibility of these components is still an ongoing challenge as the interplay of electrostatic interactions complicates normal blend phase behavior. In collaboration with Prof. Daniel Hallinan (FAMU/FSU Engineering), we are designing and investigating the phase behavior of unique precision SICs and PEO and correlating this to the ultimate conduction and transference potential of the membranes. Such studies will paint a clearer picture of what blend compositions are ideal for both miscibility and high conductivity.