ChBE Seminar: Thermotropic Order-Order Transitions and Small Molecule Modulation...
Speaker: Lawrence Sita, Professor, Chemistry and Biochemistry, UMD
Title: Thermotropic Order-Order Transitions and Small Molecule Modulation of Non-Canonical Nanostructured Mesophases of Sugar-Polyolefin Conjugates
Living coordinative chain transfer polymerization (LCCTP) is a new polymerization process that can provide access to a large variety of end-group functionalized polyolefins (x-PAOs) of very narrow polydispersity and tunable degree of polymerization from readily available and inexpensive α-olefin monomers. These x-PAOs now establish a new category of hydrophobic building block for the development of amphiphilic materials that self-assemble in both solution and in the condensed matter state to produce an assortment of highly ordered nanostructured morphologies. This talk will present the results of our most recent investigations regarding the synthesis and characterization of low molecular weight sugar-polyolefin conjugates that engage in unique dynamic temperature-driven order-order phase transitions involving several different canonical and non-canonical phases – including exceptionally stable soft matter Frank-Kasper phases. Small molecule modulation of the phase behavior of the latter and the unique stability of ultrathin films of a bicontinuous double gyroid phase with sub-2-nm feature size and down to the 2D limit of only 15 nm thickness will be discussed.
Dr. Lawrence Sita obtained his B.S. degree in 1981 from Carnegie Mellon University and his Ph.D. degree in chemistry in 1986 at the Massachusetts Institute of Technology where he was a graduate student of Professor Satoru Masamune and a postdoctoral associate in 1986 with the 2005 Chemistry Nobel Laureate, Professor Richard Schrock. He has held faculty and academic positions at Carnegie Mellon University, the California Institute of Technology, and the University of Chicago before joining the faculty in 1999 at the University of Maryland, College Park, where he is now Professor of Chemistry. Author of over 200 scientific publications and inventor on 19 issued patents, his interests include organometallic and polymer chemistry, and, in particular, the development of new catalysts for industrial processes. Awards include: a Beckman Young Investigator Award, a Dreyfus Teacher-Scholar Award, and a NSF Special Creativity Award. In 2008, Professor Sita founded the new start-up company, Precision Polyolefins, LLC, with the goal to develop and commercialize new specialty polyolefin materials that can be derived from readily available and abundant natural gas.