Linear Catenanes in Channel Confinement

Abstract

We use Langevin dynamics simulations to investigate the behavior of linear catenanes under channel confinement. We consider model poly[n]catenanes of n = 100 rings, each of m = 40 beads, and present a comprehensive analysis of their statics and dynamics in cylindrical channels of various diameters. To highlight the impact of mechanical bonding, we compare the catenane behavior to an equivalent chain of beads under the same conditions. We show that linear catenanes exhibit various confinement regimes, including a de Gennes one for intermediate channel widths and an overstretching response for strong confinement, which is unique to catenanes. The catenane’s relaxation dynamics also diverge from conventional polymers at strong confinement, presenting much slower modes. Through systematic analysis of the size, shape, and orientation of the concatenated rings and their mechanical bonds, we shed light on the underlying mechanisms driving the catenane’s static and dynamic responses to confinement.