Threading, Knotting and Impalements: Effects of Topological Interactions in Melts of Ring Polymers nd DNA Gel Electrophoresis
Davide Michieletto (University of Edinburgh)
Elucidating the physics of a concentrated suspension of ring polymers, or of an ensemble of ring polymers in a complex environment (such as that of a gel), is an important outstanding question in polymer physics. Many of the characteristic features of these systems arise due to topological interactions between polymers, or between the polymers and the environment, and it is often challenging to describe them quantitatively. Here I will present some recent research which suggests that a key role is played by inter-ring threadings (or penetrations). I will describe the physical consequences of such threadings and show that, remarkably, they can lead to a topologically-driven glassy behaviour of ring polymer melts under pinning perturbations. At the same time, I will show how threading and impalements can affect the motion of knotted ring polymers in gels and complex environments and, in turn, determine the shape of experimentally observed patterns in two-dimensional gel electrophoresis of DNA knots.
Please contact M.Gradhand@bristol.ac.uk for further information.