Large-scale molecular dynamics simulation of perfluorosulfonic acid membranes: Remapping coarse-grained to all-atomistic simulations

Abstract We combined two reverse mapping methods, a predetermined fragment database and fragment rotation, to generate atomistic configurations from coarse-grained structures. The combined method together with molecular dynamics simulations was applied to simulate perfluorosulfonic acid (PFSA) membranes with large length scales and to explore the origin of fracture under a uniaxial tensile loading. Through the analysis of voids in the deformed membrane, we found that void growth with tensile loading takes place at the boundary of the hydrophobic and hydrophilic regions, which may be the origin of the fracture in the PFSA membrane. This study demonstrates an efficient reverse mapping method, which is useful for simulating proton exchange membranes with realistic chain lengths.