Purdue University School of Chemical Engineering Graduate seminar series Prof. Bryan Boudouris School of Chemical Engineering Purdue University "Designing Macromolecules with Specific Optoelectronic and Chemical Functionalities for Advanced Membrane and Energy Conversion Applications" September 9, 2014 9:00-10:15 a.m. FRNY G140 Reception at 10:15-10:45 a.m. in Henson Atrium Abstract: : Designer polymers provide a platform by which to generate nanostructured, multifunctional materials with tailored chemical and optoelectronic functionalities whose solution-processable nature allows for the device fabrication procedures that are compatible with high-throughput (e.g., roll-to-roll coating) manufacturing processes. As such, these macromolecules offer the promise of providing tailor-made, low-cost materials solutions to some of the most pressing engineering challenges of the day. Here, we will discuss two distinct classes of functional macromolecules with tailored chemistries for implementation into separations and energy conversion applications. In the first of these efforts, we describe the synthesis, molecular characterization, and the solid-state electronic device application of an emerging class of transparent conducting macromolecules, radical polymers. Radical polymers are macromolecular materials that have flexible polymeric backbones and pendant groups that bear stable radical moieties. In contrast to almost all other semiconducting polymers, radical polymers lack backbone conjugation and are completely amorphous in the solid state. Despite this shift in macromolecular design archetype, we demonstrate that the solid-state electrical conductivity and charge carrier mobility values of a glassy model radical polymer are on par with the conductivity and mobility values of oft-used conjugated, semicrystalline polymer semiconductors [e.g., poly(3-hexylthiophene) (P3HT)]. Furthermore, upon proper tuning of the chemical functionality of the polymer chains, these radical polymers perform well as an electrode modifying layers in thin film organic photovoltaic (OPV) devices and increase the power conversion efficiencies of these OPV devices greatly. In the second of these efforts, A-B-C triblock polymers are generated using controlled radical polymerization techniques. By tuning the molecular weight, molecular weight distribution, block polymer chemical composition, and casting techniques employed, we are able to generate mechanically-robust nanoporous thin films that are well-suited for nanofiltration applications. In fact, high-flux separations (i.e., at permeabilities equal to or greater than current commercial membranes) of particles down to ~1 nm in radii are presented, which is the smallest separation performed using a block polymer template to date. Additionally, we demonstrate that, through the appropriate selection of the C-block of the triblock polymer, the chemistry of the nanopore walls can be tuned to any number of functional groups. Therefore, these tailored macromolecules provide an excellent handle by which to generate size-selective and chemically-selective separations devices. Bio: Bryan W. Boudouris is an assistant professor in the School of Chemical Engineering at Purdue University with a courtesy appointment in the Department of Chemistry. Furthermore, he is a co-founder and scientific advisor of the start-up company Anfiro, Inc. He received his B.S. in Chemical Engineering from the University of Illinois at Urbana-Champaign in 2004. After receiving his Ph.D. in Chemical Engineering from the University of Minnesota in 2009, he conducted postdoctoral research from 2009 to 2011 under the supervision of Professor Rachel Segalman at the University of California, Berkeley and Lawrence Berkeley National Laboratory. Since joining Purdue University in 2011, he has been the recipient of a number of awards at the university and national levels including the Air Force Office of Scientific Research Young Investigator Program (AFSOR YIP) award and the Defense Advanced Research Projects Agency Young Faculty Award (DARPA YFA). His group's current research interests include the design, nanostructural characterization, and implementation of homopolymers and block polymers in applications that include: polymer-based photovoltaic, thermoelectric, and memory devices; membranes with high fluxes and high selectivities; and improved sampling and detection of trace explosive residues for improved security of the homeland. Sincerely, Cindy Waibel Secretary ~ Rm 1144 Forney Hall of Chemical Engineering Purdue University 480 Stadium Mall Drive West Lafayette, IN 47907-2100 765-494-4069 Fax: 765-494-0805 leiklebe@purdue.edu<mailto:leiklebe@purdue.edu> [PurdueEngineeringLogosmall]
