Grant: Discovery Grants Program - Individual

Two classes of functional macromolecules that are driving next-generation technologies are Ion-Conducting Polymers (for electrochemical energy conversion) and Pi-Conjugated Polymers (for organic electronics). Through the design and synthesis of selected functional macromolecules this program explores the relationships between their molecular structure, morphology, and properties designed to provide a platform of fundamental knowledge and training to foster the development of next generation electrochemical energy technologies. *** Interest in ion-conducting polymers, particularly H+ and OH- conducting, has grown commensurately with the emergence of electrochemical energy conversion technologies (e.g., fuel cells, electrolyzers, redox flow batteries, solar fuel devices). Perfluorosulfonic acid (PFSA) ionomer, for which the polymer chains organize to provide ionic channels in thin films, is the quintessential proton-conducting polymer; but it has significant, well-known shortcomings. In the corollary case of alkaline media, polymers employed for hydroxide-transporting membranes typically possess quaternary ammonium groups covalently bonded to a polymer backbone, but the stability of these groups is poor in highly alkaline solutions. *** An important development in the evolution of polymer films for emerging electrochemical technologies involves exploring strategies that couple the ease-of-processing characteristics of polymers with the formation of long range order in the solid state to promote ionic transport. In the case of anion transporting materials the complexity of designing organic polymers that are stable to caustic environments is an additional challenge. The primary objective of this program of research is the exploration of synthetic strategies towards the design of novel ion-containing polymers that can be used to further understand how molecular structure controls polymer morphology and, in turn, how the morphology facilitates ion-transport in the context of developing durable solid polymer electrolytes. Sub-projects within this program address the structural control of hydrocarbon-based, proton- and hydroxide-conducting polymers, and builds on two very different oligomeric building blocks recently developed in our laboratory. In addition, in the context of developing a program in solid polymer electrolytes, we will develop an interdisciplinary field of photoelectrochemistry at pi-conjugated polymer electrodes. This program is aimed at investigating a strategy involving polymer synthesis, electrochemistry, and photoelectrochemistry of pi-conjugated polymers in solid polymer electrolytes, with the future goal of liberating hydrogen from solar-irradiated organic films. **