Radical-induced degradation mechanism of perfluorinated polymer electrolyte membrane

Characterization of the thermolysis products of Nafion membrane: A potential source of perfluorinated compounds in the environment

“…Recently, radical reactions involving the Nafion side chain have been theoretically confirmed by frontier orbital theory 55 . In this study, the calculated highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) showed a wide distribution of the electron cloud around the side chain.…”

“… In addition, the common detection of HSO 4 − and CHF 2 SO 3 − in different absorption solutions indicated cleavage of the Nafion side chain. The formation of these species was also found accompanying chemical degradation85455. In general, thermally produced radicals can react with the pendant chain under high temperatures, leading to the production of • CF(CF 3 )OC 2 F 4 SO 3 − .…”

“…Specifically, the formation of CHF 2 SO 3 − was also found in Nafion degradation using zerovalent metals in subcritical water 8 , suggesting the possible linkage of its pendant chain. Previous research on Nafion degradation has also indicated the generation of SO 4 2- and F − ions whether under in situ (fuel cell operation) or ex situ (Fenton test) conditions 9 54 55 . Recently, Yu et al 11 , using quantum mechanical calculations, proposed two mechanisms for OH • attack on Nafion polymer that also involved the formation of these two ions.…”

Theoretical analyses on water cluster structures in polymer electrolyte membrane by using dissipative particle dynamics simulations with fragment molecular orbital based effective parameters

“…[2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] Radical reaction analysis using electron spin resonance has also been conducted. [17][18][19] To elucidate the hydrated structure of Naon, many molecular calculations have been carried out to date. Voth et al analyzed the proton transport mechanism in Naon at atomistic level using the self-consistent multistate empirical valence bond (SCMS-EVB) approach.…”

Accelerated simulation of the degradation process of poly(arylene ether ketone)s containing alkylsulfonated side chains used as a proton exchange mmembrane

“…14 Uegaki et al studied individual radical-induced reactions using g-rays and demonstrated that degradation is initiated by radicals. 15 Despite these proposed degradation mechanisms, there is still not enough evidence supported by experimental data to clearly describe the detailed degradation process, especially for polymers containing exible alkylsulfonated side chains. [16][17][18] In this work, SPAEKs were successfully synthesized.…”