(516c) Understanding Ionomer Membrane Structure Via Analysis of Small Angle Scattering Profiles and Coarse-Grained Molecular Simulations

Ionomer membranes are used as proton conducting membranes for fuel cell and water electrolyzer applications due to their chemical stability, ion conductivity, and mechanical rigidity. The ion transport and mechanical properties of these membranes are dictated by the morphology of the hydrated ionomer film. The hydrophilic domains of hydrated ionomers are of particular interest as the structure and connectivity of these domains influence the ion-transport capabilities of the membrane. It is expected that the hydrophilic domain connectivity, shapes, and sizes will change with hydration, and that material processing can introduce nanoscale structural anisotropy. However, the structure of these domains is still not fully understood. In this work, we study the structure of hydrophilic domains with varying ionomer design and hydration using bottom-up and top-down approaches. In the bottom-up approach, we use coarse-grained molecular dynamics simulations with Martini_v2 model to show how real-space nanoscale structural features and multi-scale scattering profiles of simulated hydrophilic domains change with varying ionomer design.