Analysing Structure in (almost) Colloidal Sediments
- Event time: 1:00pm
- Event date: 10th November 2003
- Speaker: Matt Jenkins (University of Edinburgh)
- Location: Room 2511, James Clerk Maxwell Building (JCMB) James Clerk Maxwell Building Peter Guthrie Tait Road Edinburgh EH9 3FD GB
At the upper end of the colloidal lengthscale, particles sediment relatively rapidly to form dense solid-like ''plugs''. Contrary to the received wisdom that these sediments achieve a universal density (''random close packing''), quantitative confocal microscopy suggests that some sediments may become stable at lower densities. Related experimental studies imply a range of stable sediment densities between ''random loose packing'' and random close packing. Simple packing arrangements, seen in simulations of granular matter, show that mechanically stable structures in this range of density can be attained by mutual stabilisation (''bridging'') of particles. I will describe an attempt to isolate bridges in real colloidal sediments. It has been suggested that a stress applied to a colloidal system can induce jammed states: gravity-induced bridges in colloidal sediments may represent a simple example of this process.
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..