FACULTY OF ENGINEERINGCHEMICAL ENGINEERING


SOMER LECTURES

Somer Lectures


February 23rd and 24th, 2017
Department of Chemical Engineering



Somer Lecture I:

Design of Soft Materials using Liquid Crystallinity


Feb 23rd, 9:30

METU CCC, Auditorium A

The unique combination of long-range molecular ordering and mobility found in liquid crystals has been exploited by nature to create a range of functional and living materials. Inspired by biological designs, we are pursuing studies that seek to realize synthetic liquid crystalline materials that integrate ideas related to the engineering of strain and defects. In one  approach, we are exploring the use of elastic strain within liquid crystalline droplets to create dynamic templates that can be used to synthesize chemically patchy and non-spherical particles. In a second approach, we have used the nanoscopic physical environments created by topological defects to direct the self-assembly of biological amphiphiles in ways that have strong analogies to polymer-templated self-assembly processes. Such systems form the basis of new materials that permit ordering to propagate from the nanoscale to the optical scale with remarkable sensitivity. In a third approach, we are using the anisotropic mechanical properties of biocompatible liquid crystals to design materials than can be used to regulate the organization and function of living bacterial systems. These various lines of investigation, which encompass a broad range of supramolecular, colloidal and interfacial phenomena involving liquid crystals, will be discussed. Fundamental challenges and technological opportunities will be described.


Wang, X.; Miller, D.S.; Bukusoglu, E.; de Pablo, J.J.; Abbott, N.L., “Topological Defects in Liquid Crystals as Templates for Molecular Self-Assembly” Nature Materials, 15(1), 106-, 2016.
Wang, X., Kim, Y., Bukusoglu, E., Zhang, B., Miller, D.S., Abbott, N.L., “Experimental Insights into the Nanostructure of the Cores of Topological Defects in Liquid Crystals”, Physical Review Letters, 116, 147801, 2016


Somer Lecture II:

Understanding the Influence of Chemical Nanopatterns on Hydrophobic Interactions

Feb 24th, 9:30
METU ChE Z-17

 

The structuring of water near non-polar molecular fragments or surfaces mediates cohesive interactions (so-called hydrophobic interactions) that underlie a broad range of interfacial, colloidal and biophysical phenomena. Substantial progress has been made during the past decade towards understanding hydrophobic interactions in simple model systems, but in most biological and technological contexts, non-polar domains are found in close proximity to polar and charged functional groups. Theories and simulations hint that the effects of nanometer-scale chemical heterogeneity on hydrophobic interactions may be important, but these ideas have not been tested experimentally. In this presentation, I will show that ions immobilized adjacent to non-polar domains can substantially increase or decrease the strength of hydrophobic interactions, with the effect strongly dependent on the specific ion type. This understanding is providing a fresh starting point for optimizing molecular recognition processes as well as the self-assembly of synthetic amphiphiles, colloids, or macromolecules by judiciously placing charged groups near non-polar domains to tune hydrophobic driving forces.


Ma, C.D.; Wang, C.; Acevedo-Vélez, C.; Gellman, S.H.; Abbott, N.L., “Modulation of Hydrophobic Interactions by Proximally Immobilized Ions”, Nature, 517(7534), 347-443, 2015

 

For further information:

T: 312 210 26 01 F: 312 210 26 00
E: che@metu.edu.tr