Professor William Dichtel, Cornell University

"Porous polymers for electrical energy storage and water purification"

About the Seminar:

Polymers with many small pores exhibit enormous surfaces areas that enable us to store gaseous fuels, rapidly transport ions, immobilize catalysts and modify their selectivity, detect trace substances, and remove contaminants from liquid or gas streams. Several strategies to prepare organic materials with nanometer-size pores have proven successful. Polymers with uniform pores ranging in size from 1-5 nm are derived from monomers that organize into two or three-dimensional grids known as covalent organic frameworks (COFs). COFs were first made as insoluble powders, a form that makes it difficult to fully study their properties or make electrical contact. We developed simple and straightforward methods to grow COFs as thin films on working electrodes, which led to the first examples capable of storing and releasing electrical charge. For this application, the precise, layered arrangement of building blocks and continuous pores provided by the COF architecture contribute to their performance. An alternative strategy to introduce nanometer-size voids into polymer networks is to utilize monomers that pack inefficiently. This approach has afforded polymers derived from renewable feedstocks that rapidly remove organic pollutants from water as well as conjugated systems that detect explosives present at parts-per-trillion levels. Collectively, these examples demonstrate the value of controlling both the structure and the empty space of polymer networks.

About the Speaker:

William Dichtel is currently an Associate Professor of Chemistry and Chemical Biology at Cornell University and a Visiting Miller Professor in the Department of Chemistry at UC-Berkeley. He will join the faculty of Northwestern University in Summer 2016. His research focuses on novel organic materials and polymers, including both amorphous and crystalline porous polymers. Will received a B.S. in chemistry from MIT in 2000, then earned his PhD at UC-Berkeley in 2005 under the mentorship of Jean Frechet, then served as a joint postdoctoral researcher in the groups of Fraser Stoddart (then at UCLA) and Jim Heath (Caltech).