Improving poly(arylene piperidinium) anion exchange membranes by monomer design

Pan, Dong; Bakvand, Pegah Mansouri; Pham, Thanh Huong; Jannasch, Patric

doi:10.1039/d2ta03862e

Cited by 42 publications

(33 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The AEMs maintained their ionic conductivity and flexibility after 2000 h in 1 M KOH solution at 100 °C . At the same time, the durability and performance of the membrane can also be further improved by introducing a flexible spacer, arrangement of various cations, , cross-linking, − branching, and other methods. Gao et al synthesized a series of novel cross-linked AEMs, which combine a hydrophobic fluorine-based skeleton with a hydrophilic long flexible polycationic side chain, and showed good chemical stability when immersed in 10 M KOH for 1000 h at 80 °C …”

Section: Introductionmentioning

confidence: 95%

High Conductive Anion Exchange Membranes from All-Carbon Twisted Intrinsic Microporous Polymers

et al. 2022

View full text Add to dashboard Cite

This study obtained solution-tractable anion-selective membranes with intrinsic porous and highly ionic conductive capabilities by a convenient route. We used the coplanar structure of 9,9-dimethylxanthene to construct a rigid twisted intrinsic microporous all-carbon skeleton PDI with up to 363.4 m 2 g −1 of Brunauer−Emmett−Teller surface, and the pore was filled with a quaternary ammonium salt containing long flexible alkyl chains, which produced an efficient means of OH − transport. The conductivity of the resulting polymer (QPDI-100) is reached as high as 205 mS cm −1 at 80 °C. The size stability was determined to be good at high conductance and swelling ratio is less than 15% at 80 °C. QPDI-a exhibited good stability under alkaline conditions, and 90% of the conductivity of QPDI-100 was retained after being immersed in 1 M NaOH solution at 60 °C for 40 days. The power density of H 2 −O 2 fuel cells at 60 °C was 437.7 mW cm −2 . The prepared intrinsic porous anion exchange membranes (AEMs) demonstrate potential for the development of anion exchange membrane fuel cells. This membrane design strategy paves the way for a new generation of AEMs for the purposes of electrochemical energy conversion and storage.

show abstract

Section: Introductionmentioning

confidence: 95%

High Conductive Anion Exchange Membranes from All-Carbon Twisted Intrinsic Microporous Polymers

et al. 2022

View full text Add to dashboard Cite

show abstract

“…When it comes to piperidinium cations attached via alkyl spacers in the 1-( N )-position, the β-protons in the piperidinium rings are far less prone to elimination reactions than the β-protons in the linear alkyl spacer chains because the geometric constraint of the ring configuration increases the activation energy of the degradation reaction . By instead tethering piperidinium cations in the 4-position, all the β-protons can be placed in the rings of DMP cations which provides a very high alkaline stability. , However, developing straightforward synthetic methods to attach DMP cations in the 4-position to polymer backbones via alkyl spacers without introducing any weak links, for example, heteroatoms, is challenging.…”

Section: Resultsmentioning

confidence: 99%

“…We have previously observed that AEMs based on poly(arylene alkylene) functionalized with ASU take up less water than the corresponding DMP-functionalized AEMs at a given IEC. 34,36,38 The water uptake of PDPF-DMP-2.6, with the highest IEC, was not possible to measure above 60 °C because the sample disintegrated due to the extensive water uptake.…”

Section: Membrane Preparation and Morphologymentioning

confidence: 99%

Polyfluorenes Bearing N,N-Dimethylpiperidinium Cations on Short Spacers for Durable Anion Exchange Membranes

2023

Self Cite

View full text Add to dashboard Cite

Alicyclic quaternary ammonium cations having all the β-protons in a strain-free ring structure are in general highly base-resistant and are thus very attractive to employ for anion exchange membrane (AEM) applications. However, tethering cations such as N,N-dimethylpiperidinium (DMP) to polymer backbones without introducing any weak links is quite challenging. In the present study, we have attached pairs of piperidine rings in their 4-position to fluorene and 2,7-diphenylfluorene via methylene bridges using straightforward S N 2 reactions. These fluorenes were subsequently utilized as monomers in polyhydroxyalkylations to prepare poly(fluorene alkylene)s with different contents of the piperidine groups. AEMs were cast after quaternizing the piperidine groups to introduce DMP and spirocyclic 6-azonia-spiro-[5,5]undecane-6-ium (ASU) cations, respectively. The AEMs reached very high hydroxide ion conductivities, 100−156 mS cm −1 at 80 °C, in the ion exchange capacity range 1.8−2.4 mequiv g −1 . X-ray scattering showed ionomer peaks indicating ionic clustering with a characteristic distance d = 2.0−2.9 nm depending on the ion exchange capacity. The AEMs displayed high thermal stability, up to ∼250 °C, and 1 H NMR data indicated no degradation after storage in 5 M aq NaOH during 168 h at 90 °C. However, degradation started under very severe conditions (10 M, 90 °C) with ∼75% of the total ionic loss in all the AEMs assigned to Hofmann β-elimination. The overall results show that fluorene-based AEMs carrying DMP and ASU cations via methylene bridges display an attractive combination of ionic phase separation, thermal and chemical stability, and hydroxide conductivity, making them viable alternatives for use in alkaline fuel cells and water electrolyzers..

show abstract

“…While having the cationic group tethered to the backbone via a long alkyl chain, as in FLN‐55, allows for a phase separation capacity. [ 38 ] The hydrophobic backbone and the hydrophilic alkyl ammonium group avoid one another as the catalyst ink dries, leading to regions of high alkyl ammonium concentration and high backbone concentration. This allows for more water uptake, without causing cell flooding.…”

Section: Resultsmentioning

confidence: 99%

Phenyl‐Free Polynorbornenes for Potential Anion Exchange Ionomers for Fuel Cells and Electrolyzers

Leonard

Lehmann

Klein

et al. 2022

Advanced Energy Materials

View full text Add to dashboard Cite

Ionomers in the catalyst layer play a critical role in the performance of fuel cells and electrolyzers. Phenyl adsorption on hydrogen oxidation catalysts and electrochemical oxidation of phenyl moieties on oxygen evolution catalysts are detrimental to the alkaline devices’ performance. Here the adsorption energy of phenyl‐containing ionomers is compared to provide the rationale for implementing phenyl‐free ionomers. Density functional theory calculations indicated that the norbornane fragment has minimal adsorption energy on Pt(111) due to the absence of aromatic π electrons. A soluble quaternized polynorbornene ionomer is prepared by vinyl addition polymerization, and it exhibits high performance in both fuel cells and electrolyzers, proving the advantage of the phenyl‐free structure. This study establishes the phenyl adsorption energy‐electrode performance relationship, highlighting the importance of material interactions between the catalysts and ionomers.

show abstract

Improving poly(arylene piperidinium) anion exchange membranes by monomer design

Abstract: Poly(arylene alkylene piperidinium)s show greatly improved alkaline stability and ion conductivity in comparison to current state of the art poly(arylene piperidinium)s.

Cited by 42 publications

References 58 publications

High Conductive Anion Exchange Membranes from All-Carbon Twisted Intrinsic Microporous Polymers

High Conductive Anion Exchange Membranes from All-Carbon Twisted Intrinsic Microporous Polymers

Polyfluorenes Bearing N,N-Dimethylpiperidinium Cations on Short Spacers for Durable Anion Exchange Membranes

Phenyl‐Free Polynorbornenes for Potential Anion Exchange Ionomers for Fuel Cells and Electrolyzers

Contact Info

Product

Resources

About