January 4, 2018
11:00 AM - 12:00 PM
Speaker: Rachel Segalman
Chemical Engineering and Materials Departments
UC Santa Barbara
Title: "Functional Polymeric Ionic Liquids for Thermoelectrics and other Electrochemical Applications"
Ionic liquids (IL’s) have been suggested for applications as diverse as solubilizing cellulose, antimicrobial treatments, and electrolytes in batteries due to their molten salt properties. We have recently discovered that a polymerized cation (such as imidazolium) is an excellent host for any associated anion. As a result, polymerized ionic liquids are not just solid counterparts to IL’s, but are excellent vectors for the inclusion of a massive variety of functionalities ranging from multi-valent ions for batteries to magnetic anions. Moreover, PIL block copolymers allow orthogonal control over mechanical and morphological properties, ultimately leading to a conceptual framework for processable, tunable, multifunctional materials. In this talk, I will discuss a class of protic polymerized ionic liquids (PILs) based on imidazolium cations which exhibit high ionic conductivities in the solid state. Further, I will also discuss PIL’s that are useful for applications ranging from magnetic materials to thermoelectrics. Thermoelectric materials for energy generation have several advantages over conventional power cycles including lack of moving parts, silent operation, miniaturizability, and CO2 free conversion of heat to electricity. While highly conductive polymers are now commonplace, they generally demonstrate low thermopower. Ion conducting materials have very large Seebeck coefficients due to relatively high room temperature ionic conductivity. In this talk, I will discuss how electrochemistry and PIL design can be utilized to stabilize the Seebeck enhancement leading to stable improvements to power factor in mixed conductor thermoelectrics.