Sep 26 2019

Elastic Response and Stress Relaxation in Self-Assembled Nanoparticle Monolayers

September 26, 2019

11:00 AM - 12:00 PM


124 EIB


945 W. Taylor St., Chicago, IL 60607

Elastic Response and Stress Relaxation in Self-Assembled Nanoparticle Monolayers

Presenter: Binhua Lin, Research Professor and Executive Director of CARS, School of Molecular Engineering University of Chicago

Abstract: Self-assemblies of nanoparticles into ultra-thin quasi-2D ordered structures are materials with unique electronic, optical and magnetic properties. Liquid-vapor interfaces provide a useful platform for studying nanoparticle assemblies, especially when the interfacial energy is tailored to drive the assembly. In this talk I will first describe experiments that investigate the interplay between confinement in quasi-2D and tunable ligand interactions, which govern the rich behavior observed in self-assembled nanoparticle monolayers. I will then present the results of our study on the dynamics of nanoparticle monolayers using quasi-elastic dynamic light scattering and X-ray photon correlation spectroscopy. When measured on a sub-micrometer length scale with laser light, the presence of a solid nanoparticle monolayer does not contribute to any appreciable surface viscosity, nor does it prevent liquid surface waves from propagating. When probed on an atomic length scale with X-rays, nanoparticles move within a glassy state at lower surface pressure but are highly jammed at higher surface pressure.

Presenter bio: Binhua Lin is a research professor at the University of Chicago and the executive director of NSF’s ChemMatCARS, Sector 15, at the Advanced Photon Source, Argonne National Laboratory. NSF’s ChemMatCARS is a National User Facility dedicated to synchrotron research in chemistry and materials sciences. Lin received her PhD in physics in 1990 with Professor Pulak Dutta at Northwestern University, studying structural phase transitions of molecular monolayers at the liquid-vapor interface using synchrotron x-ray liquid surface scattering. She was a postdoc with Professor Stuart Rice from 1990 to 1994 at the University of Chicago, working on the formation and dynamics of diblock copolymer micelles at the liquid-vapor interface with laser dynamic light scattering. Lin has been with NSF’s ChemMatCARS since1994, serving first as a research beamline scientist for the liquid surface/interface scattering facility, and then as the executive director for ChemMatCARS. Lin’s current research is focused on the investigation of the structures and mechanical properties of self-assembled nanoparticle membranes.


Department of Chemical Engineering

Date posted

Sep 24, 2019

Date updated

Oct 1, 2019