Modelling of transport properties and state of water of polyelectrolytes containing various amounts of water

Atomistic molecular modelling is used to construct sulfonated PVF-based polyelectrolyte materials containing 0, 10 or 40 wt% of water. The systems contain hydronium ions, with which the classical diffusion of the hydronium ions can be simulated, and particles called protons, with which the proton hopping mechanism can be simulated. System containing 40 wt% of water is conducting. Both the proton hopping and the classical diffusion mechanisms occur in the system and neither of them is dominating. The interactions between ions are calculated and they are found to be relatively small. Diffusion coefficients of the protons, hydronium ions and the water molecules are reported and the movement of ions is studied. The location of the protons, the hydronium ions and the water molecules is studied at the atomistic level. In system containing 40 wt% of water, water clusters are seen. There are no remarkable differences between the results that are measured for similar materials or calculated in this study. (C) 2008 Elsevier Ltd. All rights reserved.