Unraveling the Effects of Self-Doping in Redox Active Polymers

About This Grant

With the support of the Macromolecular, Supramolecular, and Nanochemistry Program in the Division of Chemistry, Dr. Emily Pentzer and Dr. Jodie Lutkenhaus of Texas A&M University will design, synthesize, and characterize polymers for electrochemical energy storage. The polymers that will be developed could be created from domestic feedstocks and used in advanced battery technologies, such as flexible batteries. This work will answer the fundamental scientific questions needed to create new polymers for energy storage: how does polymer composition and structure impact the movement of electrons in and out of the polymer and how can this be improved. The answers to these questions will expand our understanding of polymers for energy storage, leading to the rapid development of new materials. Through this work, students will be trained in cross-disciplinary research such that they are prepared to be leaders in the next generation of the American STEM workforce. New educational modules on polymers for energy storage will be development for the public and shared at the Texas A&M Chemistry Open House. Non-conjugated redox active polymers will be synthesized in which redox active groups and highly polar dopant groups will be incorporated onto the same polymer scaffold. Different organization of the two types of groups will be used: random distribution, spatially defined organization, and block copolymers. Polymers will be synthesized by controlled polymerization strategies and the redox and dopant groups will be attached through high yielding click reactions. The redox active group used will be 2,2,6,6-tetramethyl-1-piperidinyloxy along with a polysiloxane backbone (for example, polydimethylsiloxane (PDMS)). The modular polymer design enables the use of azide-alkyne click chemistry to modify the PDMS-type backbones with cationic or anionic dopant units (imidazolium and trifluoromethanesulfonylimide, respectively) and/or neutral units (tetraethylene glycol). The electrochemical properties of the different polymers will be characterized in solution and in the solid state, and the heterogeneous and homogeneous rate constants and apparent diffusivity quantified and related to the polymer’s chemical structure and bulk physical properties. This research will advance our fundamental understanding of the effect of spatial arrangement and confinement on the electron transfer kinetics and overall properties of self-doping redox active polymers. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.