Influences of Chain Polarity and Molecular Weight on Ion and Polymer Dynamics in Polymerized Ionic Liquids

The results of a recent molecular dynamics simulation for a lithium ion-containing polymer reveal that lower chain polarities promote ion aggregation, while very high polarity slows down polymer segmental dynamics, both leading to reduced ionic diffusion. In this study, we employ coarse-grained molecular dynamics simulations to explore whether similar effects extend to polymerized ionic liquids. We have developed our Stockmayer fluid model, which treats the polymers as chains of charged and rotating dipolar spheres. This model allows us to systematically adjust the monomers' dipole moments and probe the system's dynamics without the need to model different polymer architectures or introduce additional molecular parameter sets. Moreover, we investigate the effect of molecular weight (chain length) and molecular polarity on the scaling laws of ion transport and viscosity, with a focus on their combined influence on ion aggregation and polymer segmental motion.