Seminar 9/19/2012 - Brad Chmelka, University of California-Santa Barbara: Functionalized Self-Assembled Materials for Photophysical and ...
Full Title: Functionalized Self-Assembled Materials for Photophysical and Electrochemical Device Applications
Bio: Prof. Chmelka's research in the Department of Chemical Engineering at the University of California, Santa Barbara seeks to develop and understand at a molecular level, novel heterogeneous materials for energy applications. He received his Ph.D. degree in Chemical Engineering from the University of California, Berkeley in 1990 under the supervision of Profs. Clayton Radke and Eugene Petersen. He was a NSF Post-Doctoral Research Fellow in Chemistry at UC-Berkeley with Prof. Alexander Pines and an NSF-NATO Post-Doctoral Research Fellow at the Max-Planck-Institut für Polymerforschung in Mainz, Germany with Prof. Hans Wolfgang Spiess. He has received a David and Lucile Packard Foundation Award, a Camille and Henry Dreyfus Teacher-Scholar Award, an Alfred P. Sloan Foundation Research Award, and has been an invited professor at universities in France, Sweden, Israel, and Spain.
Abstract: Surfactant- or copolymer-directed inorganic solids can be synthesized with a variety of compositions, structures, and morphologies that result in materials with diverse and adjustable properties. Such inorganic-organic systems are composed of dissimilar species, whose mutual self-assembly involve simultaneous considerations of thermodynamics, chemical reaction kinetics, and mass transport that are challenging to elucidate and control. The challenges are exacerbated by the multicomponent and heterogeneous characters of these hybrid solids, including surface effects and/or the incorporation of functional guest species or additives that can greatly influence material properties. Nevertheless, by combining characterization and modeling insights across multiple length scales, the compositions and structures of these versatile materials can be understood, along with their influences on macroscopic material properties.
Recent results will be presented and compared for functionalized self-assembled inorganic-organic and wholly organic materials that exhibit photovoltaic and/or ion-conduction properties. Such properties depend on molecular interactions and distributions of component species, especially at surfaces. Solid-state NMR analyses, together with X-ray scattering, electron microscopy, UV-vis spectroscopy, and modeling, provide detailed insights on complicated order and disorder in these heterogeneous materials. In particular, molecular interactions among different copolymer, electron-donating, and/or electron-accepting moieties in hybrid or organic photovoltaic materials influence how the species co-assemble during synthesis/processing and their resulting macroscopic properties. By comparison, desirable ion-conduction properties at elevated temperatures or at low humidities can be achieved by introducing and optimizing multiple functional components in a sequence of synthesis steps. The physicochemical processes and interactions that underlie the compositions, structures, and properties of functionalized self-assembled inorganic-organic and organic materials will be discussed, along with correlated molecular and macroscopic insights for photovoltaic and fuel cell applications.
All seminars are held on Wednesdays from 12:00 noon-1:00 p.m. in the Bowen Hall Auditorium Room 222. A light lunch is provided at 11:30 a.m. in the Bowen Hall Atrium immediately prior to the seminar.
Location: Bowen Hall Auditorium
Date/Time: 09/19/12 at 12:00 pm - 09/19/12 at 1:00 pm
Category: PRISM/PCCM Seminar Series