[Distinguished Lecture Series]

Nov. 6^th Wed. 2019, 4:30pm
N Center #86120, Sungkyunkwan University, Suwon

Graphene Oxides as classic 2D Colloids

Prof. So Youn Kim

Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST)

Abstract

Graphene and its oxidized form of graphene oxide (GO) have been of particular interest in material science due to their exceptional physical properties. However, relatively little attention has been paid to the GO dispersions although the state of dispersions directly affects to the material property. For example, GO can be well-dispersed in water due to their hydrophilic functionalities and form liquid crystals (LC); however, they easily form gels or glass around 1 wt%, which often act as an obstacle in GO based composite production. Thus, to understand the structure and dispersing mechanism of GO dispersions is an essential step before reaching the application stage.

In this talk, the detailed structural and rheological studies for GO dispersions are introduced with extensive scattering and rheology experiments. We first systematically investigate the phase behavior and structural evolution of GO LC suspensions under various experimental conditions and disclose how the glass transition of GO dispersions is affected particularly in the presence of strongly interacting polymers. Furthermore, microstructural transition of GO LC under shear will be discussed, suggesting the possibility of controlling the process conditions in GO employed applications.

Brief Bio

Dr. So Youn Kim is an associate professor of Energy and Chemical Engineering at Ulsan National Institute of Science and Technology (UNIST). She studied chemical engineering and earned her BS from Seoul National University in 2007. She received a Ph.D in Chemical Engineering at the University of Illinois at Urbana-Champaign in 2011 under the supervision of Charles F. Zukoski. She worked as a postdoctoral research associate at Princeton University from 2012 to 2014 with Richard A. Register. Her research interest lies on understanding fundamental interactions in soft materials from molecular level and relating to the bulk state properties. Current research focuses on the microstructure of polymer nanocomposites, interfacial dynamics at the polymer/particles, self-assembling nature of block copolymers and dispersion stability of graphene oxide solutions, using various scattering experiments.