Dynamic model of ion and water transport in ionic polymer-metal composites

In the process of electro-mechanical transduction of
ionic polymer-metal composites (IPMCs), the transport of ion and water molecule
plays an important role. In this paper, the theoretical transport models of
IPMCs are critically reviewed, with particular emphasis on the recent
developments in the latest decade. The models can be divided into three classes,
thermodynamics of irreversible process model, frictional model and Nernst-Planck
(NP) equation model. To some extent the three models can be transformed into
each other, but their differences are also obvious arising from the various
mechanisms that considered in different models. The transport of ion and water
molecule in IPMCs is compared with that in membrane electrode assembly and
electrodialysis membrane to identify and clarify the fundamental transport
mechanisms in IPMCs. And an improved transport model is proposed and simplified
for numerical analysis. The model considers the convection effect rather than
the diffusion as the major transport mechanism, and both the self-diffusion and
the electroosmosis drag are accounted for in the water flux equation.

AIP Advances 1, 040702 (2011); http://dx.doi.org/10.1063/1.3668286