P. Chiarantoni, A. Tagliabue, M. Mella, and C. Micheletti
Effect of Ring Composition on the Statics and Dynamics of Block Copolyelectrolyte Catenanes
Macromolecules (2025)
Link to online article

Abstract
We use Langevin simulations to study the effect of ring composition on the structure and dynamics of model polycatenanes with copolyelectrolyte rings, each made of one charged and one neutral block. Key observables have a nonmonotonic dependence on ring composition, including the radius of gyration, mechanical bond length, orientational correlations, and rotational relaxation times. Microscopic analysis shows that these nonmonotonicities arise from the competition between electrostatic repulsion, pulling rings apart, and topological constraints, enforcing the proximity of neighboring rings. By locking charged-neutral interfaces at the mechanically bonded regions, this interplay can induce a strong chemical orientational order along the catenane while also hindering the local relaxation dynamics. Chemical orientation defects, manifesting as neutral-neutral interfaces, can emerge too and migrate along the catenane via coupled reorientations of neighboring rings. Our results clarify how ring composition and mechanical bonds can define the properties of topological materials across different scales.