Local perturbations of colloidal suspensions
- Event time: 1:00pm
- Event date: 5th May 2003
- Speaker: Poitr Habdas (Department of Physics Emory University (Atlanta USA))
- Location: Room 2511, James Clerk Maxwell Building (JCMB) James Clerk Maxwell Building Peter Guthrie Tait Road Edinburgh EH9 3FD GB
The nature of the glass transition is one of the oldest unsolved questions in condensed matter physics. Suspensions of colloidal particles are a model system which exhibits a glass transition as the particle concentration is increased. We use confocal microscopy to observe the behavior of the system, which is possible due to the large particle size. We study the response of a colloidal suspension to a local perturbation by adding a low concentration of magnetic beads to the colloidal samples. Next, we exert a constant magnetic force on an isolated magnetic bead causing it to move and poke the colloidal particles. We study how the response to the perturbation changes with the magnetic force and the concentration of the colloidal suspension.
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..