PFSI membranes

The developed approach will be applied to model membranes whose psds closely resemble those of Nafion and similar PFSI membranes [60]. A common parameterization of experimental data for ultrafiltration membranes is given by the so-called logarithmic normal distribution [59],... 

S.L. Kohls, R.D. Noble and C.A. Koval, Effect of molecular structure and equivalent weight on facilitated transport of alkanes in Ag(I)-PFSI membranes, J. Membr. Sci., 1997, 125, 61-73. 

Application of Atomistic Modelling to PFSI Membrane Morphology... 

FIGURE 22.8 Water uptake of PFSI membranes 174, 184,185, 186,187,193,194,and221 versus their EWs by method 1 involving overnight refluxing in water. 

Perfluorosulfonic Membranes Non-PFSI Membranes High-Temperature lonomer Membranes... 

Fromtheabovereviewitcanbeconcluded that whether or not HjOj is involved in the PFSI membrane degradation mechanism in PEMFCs, its radical species are involved in the PFSI degradation process. For PFSI membranes in fuel cells, three main possible degradation pathways exist end-group unzipping, chain scission, and side-group attack. 

NMR spectroscopy is an important technique used to identify and quantify end groups in fluoro-polymers and the species extracted from degraded PFSI membranes. 

It has been reported that the presence of Fe ion and Ctf ion greatly accelerates the membrane degradation rate in the Fenton test of PFSI membranes (Kinumoto et al. 2006). Figure 5 shows effects of metal cations on membrane degradation 30% at 80°C. 

Membrane manufacturers have developed PFSI membranes with improved chemical and thermal stability as well as improved water management at high temperatures. DuPont has reported that the number of remaining hydrogen-containing end groups... 

While lots of PEMs have been developed, the sulfonated hydrocarbon polymer electrolyte (SHCPE) and perfluorocarbon sulfonated ionomer (PFSI) membranes are most widely investigated for LT-PEMFCs and DMFCs, and the PBI and its modified polymer membranes doped with H3PO4 are most widely applied to HT-PEMFCs. In the following sections, we discuss the morphologies and conducting mechanisms of the SHCPEs, PFSIs, and PBI doped with H3PO4 (PBI/H3PO4) membranes. 

XRD is used to determine the crystallinity of the PFSI membranes. According to the reports,Nafion membrane samples display a broad diffraction feature at scattering angle 29=8°-25°, which can be deconvolved into two peaks. The broad scattering peak at 26 == 15.5° and the sharp peak at 20 17.5° are assigned to diffraction maxima associated with amorphous and crystalline regions of the membranes, respectively. The crystallinity (X can be calculated with the following equation from the deconvolved peaks centered at 17.5° and 15.5° ... 

Yang, L., Tang, J., Li, L., Ai, F., Chen, X., Yuan, W. Z., Zhang, Y, Properties of precursor solution cast PFSI membranes with various ion exchange capacities and annealing temperatures. RSCAdv. 2013, 3 (20), 7289-7295. 

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