Significant improving H+/VO2+ permselectivity of Nafion membrane by modification with PDDA in aqueous isopropanol

2021 ◽  
Vol 31 (6) ◽  
pp. 839-841
Author(s):  
Julia A. Zakharova ◽  
Maria F. Zansokhova ◽  
Evgeny A. Karpushkin ◽  
Vladimir G. Sergeyev
1977 ◽  
Vol 74 ◽  
pp. 443-446
Author(s):  
R. P. Varma ◽  
R. Dayal
Keyword(s):  

1988 ◽  
Vol 53 (12) ◽  
pp. 3164-3170 ◽  
Author(s):  
Jaromír Hlavatý ◽  
Jiří Volke

Electrolysis of quaternary ammonium bromides and iodides in a divided cell with a Nafion membrane yields quaternary polyhalogenides at a carbon anode in water-ethanolic anolytes. The electrodialysis of tetrabutylammonium iodide in a cell with a Nafion membrane enables generation of tetrabutylammonium hydroxide. In electrolytic reduction of nitrobenzene in presence of 1,3-dibromopropane, N-phenylisooxazolidine results in an approx. 60% yield. This electrosynthesis takes place in dimethylformamide with tetrabutylammonium bromide at a glassy-carbon cathode in a divided cell. In the electroreduction of lobelanine hydrogensulfate in a divided cell in acid water-ethanolic media at a lead cathode prevalently lobelanidine has been obtained.


Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1000
Author(s):  
Guoxiao Xu ◽  
Juan Zou ◽  
Zhu Guo ◽  
Jing Li ◽  
Liying Ma ◽  
...  

Although sulfonic acid (SA)-based proton-exchange membranes (PEMs) dominate fuel cell applications at low temperature, while sulfonation on polymers would strongly decay the mechanical stability limit the applicable at elevated temperatures due to the strong dependence of proton conduction of SA on water. For the purpose of bifunctionally improving mechanical property and high-temperature performance, Nafion membrane, which is a commercial SA-based PEM, is composited with fabricated silica nanofibers with a three-dimensional network structure via electrospinning by considering the excellent water retention capacity of silica. The proton conductivity of the silica nanofiber–Nafion composite membrane at 110 °C is therefore almost doubled compared with that of a pristine Nafion membrane, while the mechanical stability of the composite Nafion membrane is enhanced by 44%. As a result, the fuel cell performance of the silica nanofiber-Nafion composite membrane measured at high temperature and low humidity is improved by 38%.


Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1150
Author(s):  
Aigul S. Istomina ◽  
Tatyana V. Yaroslavtseva ◽  
Olga G. Reznitskikh ◽  
Ruslan R. Kayumov ◽  
Lyubov V. Shmygleva ◽  
...  

The use of dipolar aprotic solvents to swell lithiated Nafion ionomer membranes simultaneously serving as electrolyte and separator is of great interest for lithium battery applications. This work attempts to gain an insight into the physicochemical nature of a Li-Nafion ionomer material whose phase-separated nanostructure has been enhanced with a binary plasticiser comprising non-volatile high-boiling ethylene carbonate (EC) and sulfolane (SL). Gravimetric studies evaluating the influence both of mixing temperature (25 to 80 °C) and plasticiser composition (EC/SL ratio) on the solvent uptake of Li-Nafion revealed a hysteresis between heating and cooling modes. Differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD) revealed that the saturation of a Nafion membrane with such a plasticiser led to a re-organisation of its amorphous structure, with crystalline regions remaining practically unchanged. Regardless of mixing temperature, the preservation of crystallites upon swelling is critical due to ionomer crosslinking provided by crystalline regions, which ensures membrane integrity even at very high solvent uptake (≈200% at a mixing temperature of 80 °C). The physicochemical properties of a swollen membrane have much in common with those of a chemically crosslinked polymer gel. The conductivity of ≈10−4 S cm−1 demonstrated by Li-Nafion membranes saturated with EC/SL at room temperature is promising for various practical applications.


2008 ◽  
Vol 21 (5) ◽  
pp. 578-583 ◽  
Author(s):  
Valerio Rossi Albertini ◽  
Barbara Paci ◽  
Francesco Nobili ◽  
Roberto Marassi ◽  
Marco Di Michiel
Keyword(s):  

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