Chain conformation of ring polymers under a cylindrical nanochannel confinement

TL;DR

This study combines theoretical analysis and simulations to understand how ring polymers behave when confined in cylindrical nanochannels, revealing scaling laws and the impact of chain stiffness.

Contribution

It provides new theoretical predictions and simulation validation for the conformation of ring polymers in nanochannels, including size ratios and effects of chain stiffness.

Findings

Longitudinal size scales with chain length and channel diameter

Size ratio of ring to linear polymers varies with chain stiffness

Simulation confirms theoretical scaling and ratio predictions

Abstract

We investigate the chain conformation of ring polymers confined to a cylindrical nanochannel using both theoretical analysis and three dimensional Langevin dynamics simulations. We predict that the longitudinal size of a ring polymer scales with the chain length and the diameter of the channel in the same manner as that for linear chains based on scaling analysis and Flory-type theory. Moreover, Flory-type theory also gives the ratio of the longitudinal sizes for a ring polymer and a linear chain with identical chain length. These theoretical predictions are confirmed by numerical simulations. Finally, our simulation results show that this ratio first decreases and then saturates with increasing the chain stiffness, which has interpreted the discrepancy in experiments. Our results have biological significance.