Klaus's Klusters, or: When is a Gel a Glass?
- Event time: 1:00pm
- Event date: 18th November 2002
- Speaker: Mike Cates (Formerly School of Physics & Astronomy, University of Edinburgh)
- Location: Room 2511, James Clerk Maxwell Building (JCMB) James Clerk Maxwell Building Peter Guthrie Tait Road Edinburgh EH9 3FD GB
In weak colloidal gels, the bonds between particles can break and reform; but globally the system is a nonergodic gel of finite elastic modulus. Why? A new approach to this question, recently made quantitative by Klaus Kroy, views gelation as the glass transition of ''effective particles'' produced by a cluster aggregation process that is effectively irreversible only at short length scales. At large length scales the clusters are mobile in principle, but can still arrest due to crowding, creating the gel. The glass transition of the clusters is treated by mode coupling theory (MCT), but almost no knowledge of MCT is required to appreciate the elegant implications of this new theory.
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..