The swelling behaviour of perfluorinated ionomer membranes in ethanol/water mixtures

The effect of methanol and ethanol cross-over on the performance of PtRu/C-based anode DAFCs

“…In general, the membrane uptake of pure polar solvent is higher than that of pure non-polar solvent. However, when water is combined with an adsolvent, the degree of swelling is inversely related to the polarity of the adsolvent [18]. Fig.…”

Ethanol crossover phenomena and its influence on the performance of DEFC

“…2 that the swelling degree of Nafion ® membrane gets higher with ethanol solution concentration increment. There exit microscopic and macroscopic or bulk swelling for Nafion ® membranes in aqueous ethanol solutions [19]. The microscopic swelling is related to the amount of water adsorbed by the ionic clusters while the macroscopic swelling is related to ethanol which can penetrate and plasticize the fluorocarbon matrix, resulting in an increase in the number density of clusters and producing an enhanced macroscopic swelling.…”

Investigation of the Morphological Changes in Nafion Membranes Induced by Swelling with Various Solvents

“…Though not addressed as part of this investigation, the partitioning effect has been observed by other researchers for membranes swollen with water/alcohol mixtures, in which the alcohol was found to plasticize the Nation matrix enhancing macroscopic swelling relative to that achievable in either pure solvent [20]. As previously noted [10,11], the slopes of both curves (ionic spacing vs. volume fraction solvent, crystal peak spacing vs. volume fraction solvent) would have to match if the structure were to be envisioned as wholly comprised of crystalline platelets separated by ion-rich channels.…”