(247ah) Molecular Dynamics Simulations Study of Poly(p-phenylene oxide) Based Polymer Membrane for Alkaline Fuel Cells

Molecular Dynamics Simulations Study
of Poly(p-phenylene oxide) Based
Polymer Membrane for Alkaline Fuel Cells

Hongchao Pan, Justin Hooper, Dmitry Bedrov

ABSTRACT:
To study thermophysical, structural, and transport properties of
anion-conductive polymer membrane utilized in alkaline fuel cell applications, atomistic
molecular dynamics (MD) simulations employing a polarizable force field have
been conducted. The force field was parameterized to fit data from ab initio calculations for binding and
conformational energies and optimal geometries. A series of systems comprised
of p-phenylene oxide dimers and oligomers with
tri-methyl ammonium side groups have been simulated in aqueous solutions with
hydroxide anion at variety of solution composition (anion-water molar ratios of
1:10, 1:17, and 1:500). Detailed analysis of polymer conformational distributions
and dynamics, spatial distribution of water and anions and their dynamics in
the polymer matrix were correlated with the underlying heterogeneous structure
of membrane. The influence of the length of the alkyl tethers attached to the
ammonium-based cation side groups have been also
investigated.