Hydroxide ions transportation in polynorbornene anion exchange membrane

In this paper, a series of amorphous polynorbornene cells were constructed, and the microstructures of the membranes and the transports of OH-in the membranes were optimized at different temperatures and water contents. The relationships between the microstructure of polynorbornenes and the transport of hydroxide ions were investigated by molecular dynamic (MD) simulations. The mobility of hydroxide ions was studied by the mean square displacement (MSD) curves. The results of the radial distribution functions (RDFs) of quaternary ammonium groups indicated that the functional groups were evenly distributed around the water channels. The RDFs of the hydroxide ions and the water molecules suggested that the hydroxide ions were surrounded by two layers of water shells. The migration of hydroxide ions occurred between two layers of water molecules, depending on the interactions of the hydrogen bonding. As the kinetic energy of a molecule increased with increasing the temperature, hydroxide ions moved faster at higher temperatures. (c) 2018 Elsevier Ltd. All rights reserved.