Nafion membranes, morphology simulations

Various simulation techniques, as applied to PEFCs, differing in the degree of coarseness and the basie equations solved have been reviewed [10-14]. In contrast to these reviews, in which the transport phenomena in ionomer membranes are discussed in detail, we will consider the problems related to the modeling of Nafion morphology, with the emphasis on the role of water content. 

Galperin DY, Khokhlov AR. Mesoscopic morphology of proton-conducting polyelectrol5de membranes of Nafion tjqie a self-consistent mean field simulation. Macromol Theory Simul 2006 15(2) 137-46. 

DPD simulations have been analyzed in view of the microsegregated structure of hydrated Nafion at various X (Hayashi et al., 2003 Vishnyakov and Neimark, 2005 Yamamoto and Hyodo, 2003). A typical structure is depicted in Figure 2.11. Size and separation distance of ionic clusters were found to increase approximately linearly with X. Upon increasing X, the membrane undergoes a percolation transition from isolated hydrophilic clusters to a 3D network of randomly interconnected water channels. Wu et al. (2008) applied extensive DPD simulations to compare the morphologies of Nafion, short sidechain (SSC) PFSA PEMs of Solvay-Solexis, and 3M... 

Dorenbos, G. Suga, Y Simulation of equivalent weight dependence of Nafion morphologies and predicted trends regarding water diffusion. J. Membrane Sci. 330 (2009), pp. 5-20. 

FIG U RE 1.18 Simulated morphologies of Nafion and SPEK membranes. (Reproduced with permission from Kreuer, K.D., J. Membr. ScL, 185, 29, 2001.)... 

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