Investigating the dynamics of ring polymers with different internal topologies

Abstract

The aim of this thesis is to investigate relaxation times of different polymer segments in topologically modified ring polymeric systems. These topologically modified ring polymers are relevant in the context of bacterial chromosome organizations. But it is expected that new emergent polymer physics phenomena will result as a consequence of the different topological modifications within ring polymers. In particular, in an already published paper in the soft matter group of Prof. Apratim Chatterji, there are set of 12 different architectures that have already been designed to study the role of internal loops in organization of polymer segments within a confining cylinder. In addition, the group is also currently investigating the organization of polymer segments as a consequence of internal loops in spherical confinements. Due to the modified architecture, the dynamics (relaxation properties) of loops with respect to each other and thereby the entire polymeric system can be very different from what is known for ring or linear polymers. Single small loops repel other loops entropically and likely entangle less compared to linear polymeric systems. The relatively fast relaxation of internal loops could lead to a much faster relaxation in topologically modified ring polymers as compared to standard ring polymers. We have focused on four different architectures : Linear Chain, Ring, ”Inverted-8”/Dumbbell and Arc2. We have shown results of how their size is affected due to introduction of the cross-links. Also, how their diffusion properties change and how the various conformation vectors within these polymers relax. We have also calculated the scaling through our data for these cases and compared it across these architectures.