Anion-exchange membranes containing diamines: preparation and stability in alkaline solution

Komkova, E. N.; Stamatialis, Dimitrios; Strathmann, H.; Weßling, Matthias

doi:10.1016/j.memsci.2004.06.026

Cited by 227 publications

(171 citation statements)

References 11 publications

Supporting

Mentioning

164

Contrasting

Order By: Relevance

“…A few other promising cations evaluated include pentamethylguanidium, quaternarized diazabicylco[2.2.2]octane, N,N,N,N-tetramethyl-hexanediammonium, 1-methylimidazoliium, and tris(2,4,6-trimethoxyphenyl) phosphonium (16,(24)(25)(26)(27)(28)(29)(30)(31)(32). Most of these cations exhibit some level of alkaline stability, but comparison of the reported alkaline stability data are difficult because most of the experiments performed were carried out under different conditions (e.g., alkali concentrations and temperature) and used different characterization methods to assess stability (e.g., 1D 1 H NMR, infrared spectroscopy, change in ion-exchange capacity, and change in ion conductivity).…”

mentioning

confidence: 99%

Two-dimensional NMR spectroscopy reveals cation-triggered backbone degradation in polysulfone-based anion exchange membranes

Arges

Ramani

2013

Proc. Natl. Acad. Sci. U.S.A.

422

295

View full text Add to dashboard Cite

Anion exchange membranes (AEMs) find widespread applications as an electrolyte and/or electrode binder in fuel cells, electrodialysis stacks, flow and metal-air batteries, and electrolyzers. AEMs exhibit poor stability in alkaline media; their degradation is induced by the hydroxide ion, a potent nucleophile. We have used 2D NMR techniques to investigate polymer backbone stability (as opposed to cation stability) of the AEM in alkaline media. We report the mechanism behind a peculiar, often-observed phenomenon, wherein a demonstrably stable polysulfone backbone degrades rapidly in alkaline solutions upon derivatization with alkaline stable fixed cation groups. Using COSY and heteronuclear multiple quantum correlation spectroscopy (2D NMR), we unequivocally demonstrate that the added cation group triggers degradation of the polymer backbone in alkaline via quaternary carbon hydrolysis and ether hydrolysis, leading to rapid failure. This finding challenges the existing perception that having a stable cation moiety is sufficient to yield a stable AEM and emphasizes the importance of the often ignored issue of backbone stability.alkaline fuel cells | anion exchange membrane degradation | water electrolysis | quaternary benzyl ammonium cations T here have been intensive research efforts directed toward the development of anion exchange membranes (AEMs) for solidstate alkaline fuel cells (AFCs) and water electrolyzers in recent years (1-6). These devices permit the use of non-platinum-groupmetal electrocatalysts for the oxygen reduction/evolution and hydrogen oxidation/evolution reactions (7-11). Besides their use in AFCs, AEMs are highly relevant for other electrochemical energy conversion/storage devices such as redox flow batteries, electrodialysis stacks, and metal-air batteries (6,(12)(13)(14). The renewed interest in AFCs has led to many studies directed toward improving the hydroxide ion conductivity of AEMs, a property that is inherently limited by the lower intrinsic mobility of the hydroxide ion. Approaches have included investigating new fixed cation chemistries and/or modification of the polymer electrolyte membrane network (e.g., cross-linking, spacer chain pendants, and block copolymers) (15-17). These efforts have facilitated an order of magnitude gain in hydroxide ion conductivity (roughly 10) (15,18,19). AEMs have traditionally exhibited poor chemical stability in alkaline environments. The poor alkaline stability of AEMs is an important issue that has received much less attention than AEM ionic conductivity. This issue has limited the use of AEMs in applications that involve exposure to hydroxide ions, a potent nucleophile (12). The primary AEM degradation modes involve hydroxide ion attack on the fixed cation groups of AEMs, leading to Hoffman elimination (1, 10, 11), direct nucleophilic substitution (1-3), and chemical rearrangements induced through ylide intermediate formation (2,3,(20)(21)(22). Each of these degradation mechanisms results in rapid loss of ion exchange capacity, and hence ionic co...

show abstract

mentioning

confidence: 99%

Two-dimensional NMR spectroscopy reveals cation-triggered backbone degradation in polysulfone-based anion exchange membranes

Arges

Ramani

2013

Proc. Natl. Acad. Sci. U.S.A.

422

295

View full text Add to dashboard Cite

show abstract

“…[6][7][8] Benzyltrimethyl ammonium (BTMA + ) cation has been the most commonly employed cation in AEMs and has been investigated extensively for its application in AMFC. [9][10][11][12][13][14][15][16] Previous experimental measurements had shown that the concentration of unsubstituted BTMA + cation decreased by ∼10% within 29 days in 5 mol/L NaOH at 80…”

mentioning

confidence: 99%

Hydroxide Degradation Pathways for Substituted Benzyltrimethyl Ammonium: A DFT Study

Long

Pivovar

2014

ECS Electrochemistry Letters

View full text Add to dashboard Cite

“…Preparation of the APEI followed a two-step reaction: (1) chloromethylation of PEI using chloromethyl methyl ether (CMME) in the presence of ZnCl 2 , a Friedel-Crafts catalyst, and then (2) amination by means of TEA. 11,12 Initially, PEI was chloromethylated by dissolving PEI in dichloroethane while stirring to form a 8 wt% solution. Then, the catalyst ZnCl 2 , was added at 10 wt% of the PEI and a desired amount of CMME was introduced very slowly while stirring at 60 o C for 3 h. Once completed, the solution was washed with methanol numerous times and dried at 50 o C for 24 h in a forced convection oven.…”

Section: Methodsmentioning

confidence: 99%

Synthesis of Aminated Poly(ether imide) for the Preparation of Bi-polar Membranes and Their Application to Hypochlorite Production through the Surface Direct Fluorination

Kim¹,

Kang²,

Rhim³

et al. 2015

Polymer Korea

View full text Add to dashboard Cite

초록: 폴리페닐렌옥사이드(PPO)와 폴리에테르이미드(PEI)에 대해 각각 설폰화(SPPO) 및 아민화(APEI)반응이Abstract: Poly(phenylene oxide) (PPO) and polyether imide (PEI) were sulfonated and aminated to create sulfonated poly(phenylene oxide) (SPPO) and aminated polyether imide (APEI), respectively. Characterization of the SPPO and APEI were performed via measurements of FTIR, thermogravimetry (TGA), swelling degree, ion exchange capacity (IEC), and ion conductivity. Next, the surfaces of these membranes were modified by surface fluorination at room temperature. The surface fluorinated SPPO and APEI membranes underwent characterization again for the mentioned measurements to determine any differences. The 3 types of bi-polar membranes were prepared by varying the IEC of the APEI at a fixed SPPO IEC value, which were applied to the low and high NaCl concentration of feed solution at the different current density, respectively. The hypochlorite concentration derived from the surface fluorinated membranes was dependent on the IEC of the APEI and ranged from 491 to 692 ppm at 80 mA/m 2 . At low current density of 5 mA/m 2 , the hypochlorite concentrations ranged from 18 to 28 ppm for the 4 hrs surface fluorinated membranes and their durability increased greatly.

show abstract

Anion-exchange membranes containing diamines: preparation and stability in alkaline solution

Cited by 227 publications

References 11 publications

Two-dimensional NMR spectroscopy reveals cation-triggered backbone degradation in polysulfone-based anion exchange membranes

Two-dimensional NMR spectroscopy reveals cation-triggered backbone degradation in polysulfone-based anion exchange membranes

Hydroxide Degradation Pathways for Substituted Benzyltrimethyl Ammonium: A DFT Study

Synthesis of Aminated Poly(ether imide) for the Preparation of Bi-polar Membranes and Their Application to Hypochlorite Production through the Surface Direct Fluorination

Contact Info

Product

Resources

About