Department of Physics, Engineering Physics & Astronomy

Department of Physics, Engineering Physics & Astronomy
Department of Physics, Engineering Physics & Astronomy

A Twisted Tale of Conformational Isomerism and Chain Packing in Conjugated Polymers

Michael Winokur
University of Wisconsin-Madison

Wednesday, October 26, 2005
10:30 AM @ Stirling 501

Abstract:

Although most conjugated polymer applications are based on specific electronic or optical properties there is widespread recognition that structural order, both along the polymer chain and between chains, is ultimately responsible for defining their function in virtually all settings. The two-fold coordination geometry of the covalent bonds that constitutes most polymer chains creates a complex setting in which torsional degrees of freedom play a dominant role. There are qualitative similarities with biopolymers in which secondary or tertiary structural responses (i.e., folding or aggregation) are potentially more important for function than that of the primary chemical sequencing or that of the mean structure over larger length scales. These attributes are extremely sensitive to even small changes in the chemical architecture and environmental conditions. This talk will discuss some of the more unusual structure/property relationships in two prototypical sigma- and pi- conjugated polymer families, functionalized polysilanes and polyfluorenes and molecular level approaches for deciphering these structural attributes.