Molecular Dynamics Simulations of Hydroxide Solvation and Transport in Anionic Exchange Membranes

Abstract

In this work we present efforts to understand the properties of hydroxide in anion exchange membranes. First, we review the available reactive hydroxide molecular models and rationalize the selection of a model. Then aqueous cation systems are introduced as an analogue for anion exchange membranes. We show that hydroxide solvation structure has minimal temperature dependence, but that the concentration has a strong effect dependent on the identity of the cation. Last the electrostatic potential is calculated for four cations used in anion exchange membranes. The electrostatic field is shown to have a very different size, shape and intensity for the cations considered, which we postulate will lead to different local environments around the cations.