Recast Nafion‐117 thin film from water solution

Gas Sorption, Diffusion, and Permeation in Nafion

“…The chain packing in Nafion can be qualitatively assessed with the WAXD spectrum presented in Figure . The spectrum indicates semicrystalline behavior of Nafion represented by the crystalline peak at 2θ = 17.7° and two amorphous halo peaks at 2θ = 16.8° and 39.3° consistent with previously reported data. − The relative crystallinity calculated by fitting the crystalline and amorphous peaks from Figure is 11.4%. These results agree with previously reported WAXD data for Nafion with crystallinity values ranging between 12 and 22%. , Nafion shows a bimodal amorphous distribution comprising regions with average chain d -spacings of 2.3 and 5.3 Å calculated from Bragg’s equation ( d = λ/2 sin θ).…”

Gas Sorption, Diffusion, and Permeation in Nafion

“…The chain packing in Nafion can be qualitatively assessed with the WAXD spectrum presented in Figure . The spectrum indicates semicrystalline behavior of Nafion represented by the crystalline peak at 2θ = 17.7° and two amorphous halo peaks at 2θ = 16.8° and 39.3° consistent with previously reported data. − The relative crystallinity calculated by fitting the crystalline and amorphous peaks from Figure is 11.4%. These results agree with previously reported WAXD data for Nafion with crystallinity values ranging between 12 and 22%. , Nafion shows a bimodal amorphous distribution comprising regions with average chain d -spacings of 2.3 and 5.3 Å calculated from Bragg’s equation ( d = λ/2 sin θ).…”

Effects of Ion Exchange on the Free Volume and Oxygen Permeation in Nafion for Fuel Cells

“…WAXD patterns for dehydrated Nafion with different cations recorded at room temperature are displayed in Figure . A sharp peak at around 2θ = 17° is superimposed on an amorphous halo over a range of 2θ = 12−22°, in agreement with Laporta et al and Fujimura et al The peak can be indexed as the (100) reflection of the hexagonal structure of polytetrafluoroethylene (PTFE)-like crystallites in Nafion. − The crystalline reflection around 17° is weakened in the Na + and K + forms in comparison with that in the H + form, suggesting that in ion-exchanged Nafion large alkali ions make the regular arrangement of the molecular chains difficult and the crystallinity is decreased. If we use the method of Park and Yamazaki, the crystallinity of the H + form is very roughly ∼27%, whereas that of the ion-exchanged samples is ∼24%.…”

“…A sharp peak at around 2θ ) 17°is superimposed on an amorphous halo over a range of 2θ ) 12-22°, in agreement with Laporta et al 42 and Fujimura et al 43 The peak can be indexed as the (100) reflection of the hexagonal structure of polytetrafluoroethylene (PTFE)-like crystallites in Nafion. [44][45][46][47][48] The crystalline reflection around 17°is weakened in the Na + and K + forms in comparison with that in the H + form, suggesting that in ionexchanged Nafion large alkali ions make the regular arrangement of the molecular chains difficult and the crystallinity is decreased.…”

Impact of Heating on the Structure of Perfluorinated Polymer Electrolyte Membranes: A Positron Annihilation Study

“…Figure 5 shows WAXD patterns recorded at room temperature for Nafion NR212 and Aquivion E8705 asreceived and after heating at 160 8C. For both the samples, a sharp peak at around 2u ¼ 178 is superimposed on an amorphous halo over a range of 2u ¼ 12-228, in agreement with Heijden et al [23] and Laporta et al [24] . This sharp peak can be indexed as the 100 reflection of the hexagonal structure of PTFE-like crystallites.…”

Gas Sorption, Diffusion, and Permeation in Nafion

“…The chain packing in Nafion can be qualitatively assessed with the WAXD spectrum presented in Figure . The spectrum indicates semicrystalline behavior of Nafion represented by the crystalline peak at 2θ = 17.7° and two amorphous halo peaks at 2θ = 16.8° and 39.3° consistent with previously reported data. − The relative crystallinity calculated by fitting the crystalline and amorphous peaks from Figure is 11.4%. These results agree with previously reported WAXD data for Nafion with crystallinity values ranging between 12 and 22%. , Nafion shows a bimodal amorphous distribution comprising regions with average chain d -spacings of 2.3 and 5.3 Å calculated from Bragg’s equation ( d = λ/2 sin θ).…”

Effects of Ion Exchange on the Free Volume and Oxygen Permeation in Nafion for Fuel Cells

“…WAXD patterns for dehydrated Nafion with different cations recorded at room temperature are displayed in Figure . A sharp peak at around 2θ = 17° is superimposed on an amorphous halo over a range of 2θ = 12−22°, in agreement with Laporta et al and Fujimura et al The peak can be indexed as the (100) reflection of the hexagonal structure of polytetrafluoroethylene (PTFE)-like crystallites in Nafion. − The crystalline reflection around 17° is weakened in the Na + and K + forms in comparison with that in the H + form, suggesting that in ion-exchanged Nafion large alkali ions make the regular arrangement of the molecular chains difficult and the crystallinity is decreased. If we use the method of Park and Yamazaki, the crystallinity of the H + form is very roughly ∼27%, whereas that of the ion-exchanged samples is ∼24%.…”

“…A sharp peak at around 2θ ) 17°is superimposed on an amorphous halo over a range of 2θ ) 12-22°, in agreement with Laporta et al 42 and Fujimura et al 43 The peak can be indexed as the (100) reflection of the hexagonal structure of polytetrafluoroethylene (PTFE)-like crystallites in Nafion. [44][45][46][47][48] The crystalline reflection around 17°is weakened in the Na + and K + forms in comparison with that in the H + form, suggesting that in ionexchanged Nafion large alkali ions make the regular arrangement of the molecular chains difficult and the crystallinity is decreased.…”

Impact of Heating on the Structure of Perfluorinated Polymer Electrolyte Membranes: A Positron Annihilation Study

“…Figure 5 shows WAXD patterns recorded at room temperature for Nafion NR212 and Aquivion E8705 asreceived and after heating at 160 8C. For both the samples, a sharp peak at around 2u ¼ 178 is superimposed on an amorphous halo over a range of 2u ¼ 12-228, in agreement with Heijden et al [23] and Laporta et al [24] . This sharp peak can be indexed as the 100 reflection of the hexagonal structure of PTFE-like crystallites.…”

Gas Sorption, Diffusion, and Permeation in Nafion

“…The chain packing in Nafion can be qualitatively assessed with the WAXD spectrum presented in Figure . The spectrum indicates semicrystalline behavior of Nafion represented by the crystalline peak at 2θ = 17.7° and two amorphous halo peaks at 2θ = 16.8° and 39.3° consistent with previously reported data. − The relative crystallinity calculated by fitting the crystalline and amorphous peaks from Figure is 11.4%. These results agree with previously reported WAXD data for Nafion with crystallinity values ranging between 12 and 22%. , Nafion shows a bimodal amorphous distribution comprising regions with average chain d -spacings of 2.3 and 5.3 Å calculated from Bragg’s equation ( d = λ/2 sin θ).…”

Effects of Ion Exchange on the Free Volume and Oxygen Permeation in Nafion for Fuel Cells

“…WAXD patterns for dehydrated Nafion with different cations recorded at room temperature are displayed in Figure . A sharp peak at around 2θ = 17° is superimposed on an amorphous halo over a range of 2θ = 12−22°, in agreement with Laporta et al and Fujimura et al The peak can be indexed as the (100) reflection of the hexagonal structure of polytetrafluoroethylene (PTFE)-like crystallites in Nafion. − The crystalline reflection around 17° is weakened in the Na + and K + forms in comparison with that in the H + form, suggesting that in ion-exchanged Nafion large alkali ions make the regular arrangement of the molecular chains difficult and the crystallinity is decreased. If we use the method of Park and Yamazaki, the crystallinity of the H + form is very roughly ∼27%, whereas that of the ion-exchanged samples is ∼24%.…”

“…A sharp peak at around 2θ ) 17°is superimposed on an amorphous halo over a range of 2θ ) 12-22°, in agreement with Laporta et al 42 and Fujimura et al 43 The peak can be indexed as the (100) reflection of the hexagonal structure of polytetrafluoroethylene (PTFE)-like crystallites in Nafion. [44][45][46][47][48] The crystalline reflection around 17°is weakened in the Na + and K + forms in comparison with that in the H + form, suggesting that in ionexchanged Nafion large alkali ions make the regular arrangement of the molecular chains difficult and the crystallinity is decreased.…”

Impact of Heating on the Structure of Perfluorinated Polymer Electrolyte Membranes: A Positron Annihilation Study

“…Figure 5 shows WAXD patterns recorded at room temperature for Nafion NR212 and Aquivion E8705 asreceived and after heating at 160 8C. For both the samples, a sharp peak at around 2u ¼ 178 is superimposed on an amorphous halo over a range of 2u ¼ 12-228, in agreement with Heijden et al [23] and Laporta et al [24] . This sharp peak can be indexed as the 100 reflection of the hexagonal structure of PTFE-like crystallites.…”