Penetration of linear chains into semiflexible knotted rings in linear-ring blends

Abstract

Threading of ring chains by linear chains has a great effect on the long-time dynamics of the ring chains in linear-ring blends. In this paper, we performed coarse-grained molecular dynamics simulations on the mixtures of linear and ring chains to investigate the effects of chain rigidity on the penetration of knotted rings threaded by linear chains. As the chain rigidity Kb of rings increases, non-trivial rings exhibit a non-monotonous dependence of the chain-penetration on chain rigidity Kb, and the semiflexible knotted rings with Kb = 10 have the maximum chain-penetration ability. This anomalous result is due to the two competing effects: As the chain rigidity of rings increases, one is that the swollen of rings can create more free space in favour of chain penetration, and another is that the formation of ordered clusters for rings in which rings tend to get parallel to each other can strongly hinder linear chains to penetrate into rings. Meanwhile, the transition from disordered to ordered phase for the trivial rings in linear-ring blends is a quite sensitive dependence on the chain rigidity of rings, resulting in a sudden transition at Kb = 12.