Cain Department of Chemical Engineering SEMINAR

Liquid Crystals for Responsive Materials Design

Monirosadat (Sanaz) Sadati
Postdoctoral Researcher, Institute for Molecular Engineering
The University of Chicago

The alignment of liquid crystal molecules is exquisitely sensitive to molecular and chemical interfacial binding events; these events can be amplified over relatively long distances, thereby providing the basis for a wide range of applications, from display technologies and optical devices to biosensors. A molecular-level understanding of the structure of liquid crystal interfaces is therefore central to such technologies. In this seminar, I will present a detailed view of the molecular organization of synthetic nematic and smectic liquid crystalline materials at interfaces, which we have generated through the combined use of synchrotron X-ray reflectivity measurements and molecular simulations. I will then discuss some of the unique responses of synthetic nematic liquid crystalline materials to the interfacial self-assembly of biological amphiphiles or the aggregation of proteins, and explain how such responses can be used to detect complex assembly processes, such as the very early stages of amyloid fibril formation. A second part of this seminar will discuss how more complex liquid crystalline behaviors and morphologies can be arrived at by introducing chiral molecules. More specifically, I will focus on the blue phases of liquid crystals, which consist of liquid, highly ordered lattice structures that are stabilized by networks of line defects. These structures can reflect light in a highly selective manner, and are therefore of interest for optical applications. Unfortunately, they are only stable in a very narrow temperature range. I will explain how the coupling of chirality, geometrical confinement, mechanical deformation and polymerization of defect structures can enable the engineering of new morphologies that are stable over a much wider range of conditions. I will conclude by discussing some of the potential uses of these materials, along with some of the questions and challenges that remain to be addressed.

Tuesday, January 23, 2018
1202 Patrick Taylor Hall

Coffee will be served at 10:30am