Dissipative Particle Dynamics Simulation of Multiscale Phase-Separated Structures in Graft-Type Polymer Electrolyte Membrane by Optimization Compared to Scattering Analysis

This study showed that an optimized structural simulation model for polymer materials using actual measurements as an indicator can enable the expression of ion channel structures as digital values that affect ion conductivity. The hierarchical structure of polymer electrolyte membranes (PEMs) significantly influences their ionic conductivity and durability. Dissipative particle dynamics (DPD) simulations can reproduce the multiscale phase-separated structures in graft-type PEMs by optimizing conservation parameters and coupling force terms in comparison with small-angle neutron scattering (SANS) profiles. The most decisive χ-parameters are evaluated by the appropriate terminal group and charge assignments of coarse-grained particles. Here, the simulated scattering profiles of ion channels and hydrophilic-hydrophobic phase-separated structures were adjusted by tuning the spring constant between the DPD particles to those in the SANS profiles. The Teubner–Strey model analysis of the simulated scattering profile showed the average diameter d of the ion channel and its deviation ε to be 1.9–2.0 nm and ±0.5 nm, respectively.