Conformation and Dynamics of Nonconcatenated Ring Polymers under Planar Confinement

Understanding the segregation of nonconcatenated ring polymers in a restricted volume is important to the biological field, because ring polymers have been proven to be a good model to study DNA organization in the cell nucleus. From our previous study, linear polymers segregate under extreme cylindrically-confined systemsdue to the strong correlation hole effect that is enhanced by the confining surfaces. Unlike linear polymers, the correlation hole effect of ring polymers is much stronger under confined systems since there are no chain ends. In this study, we use MD simulation to investigate the chain conformations and dynamics of ring polymers under planar confinements with different thicknesses (H = 5, 7, 10, 14 and 20σ) that span from extreme confined case to bulk like case. Our results show that conformations of ring polymers are similar to the linear polymers under planar confinements, except that ring polymers are less compressed along the direction normal to the walls. On correlation hole effect analysis, we distinguish the segregation regime from the mixing regime based on self-density calculation for ring polymers. From the diffusion and local chain relaxation dynamics, we observe that chain dynamics are primarily affected by the friction from walls.