Imaging the microstructure of colloidal suspensions to understand their non-Newtonian flow behavior
- Event time: 1:00pm
- Event date: 20th May 2013
- Speaker: Neil Lin (Physics Department Cornell University)
- Location: Room 2511, James Clerk Maxwell Building (JCMB) James Clerk Maxwell Building Peter Guthrie Tait Road Edinburgh EH9 3FD GB
Complex fluids demonstrate many fascinating non-Newtonian flows. Colloidal suspensions are a particularly interesting complex fluid because they display Newtonian, shear thinning and even shear thickening behaviors at different shear rates. Although the mechanical response of colloids has been studied extensively using conventional rheological techniques, without direct imaging of the suspension microstructure it has been difficult to elucidate the mechanisms underlying the suspension's non-Newtonian response. Here, we use a fast confocal-rheoscope to study the structure response of sheared colloidal suspensions and relate this response to their rheological properties. In this talk, I will introduce this general experimental approach of linking microstructure with rheological properties. I will also illustrate the capabilities of this approach by presenting results about the shear thinning , shear induced structure, and shear thickening behavior of this fascinating class of materials.
This is a weekly series of informal talks given primarily by members of the soft condensed matter and statistical mechanics groups, but is also open to members of other groups and external visitors. The aim of the series is to promote discussion and learning of various topics at a level suitable to the broad background of the group. Everyone is welcome to attend..