Dissipative Particle Dynamics simulation hydrated Nafion EW ۱۲۰۰ as fuel cell membrane in nanoscopic scale

The microphase separation of hydrated perfluorinated sulfonic acid membrane Nafion was investigated using Dissipative Particle Dynamics (DPD). The nafion as a polymer was modelled by connecting coarse grained beads which corresponds to the hydrophobic backbone of polytetrafluoroethylene and perfluorinated side chains terminated by hydrophilic end particles of sulfonic acid groups [۱, ۲]. Each four water molecule coarse grained in a bead to obtain the same bead size as built in Nafion model. The morphology of hydrated Nafion is studied for branching density of ۱۱۴۴, an example of Nafion EW۱۲۰۰, water content of ۱۰%, ۲۰% and ۳۰% and polymer molecular weight of ۵۷۲۰, ۱۱۴۴۰ and ۱۷۱۶۰. The results show water particles and hydrophilic particles of Nafion side chains spontaneously form aggregates and are embedded in the hydrophobic phase of Nafion backbone. The averaged water pore diameter and the averaged water clusters distance were found to rises with water volume fraction.

Keywords:

Fuel Cell , Membrane , Nafion , Microphase separation , water network , DPD