Reduction of the monomer quantities required for the preparation of radiation-grafted alkaline anion-exchange membranes

Poynton, Simon D.; Varcoe, John R.

doi:10.1016/j.ssi.2015.04.013

Cited by 18 publications

(18 citation statements)

References 34 publications

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“…It is therefore vital to significantly reduce the quantity of VBC monomers used in the grafting step. This has been carried out most widely by the dilution of VBC with organic solvents such as propanol 4,21 and toluene. 22 Specifically, our group has previously used propan-2-ol diluent to lower the VBC concentration to 20 vol% for grafting onto ETFE film that had been electron-beam irradiated to a high 70 kGy absorbed dose (the prior state-of-the-art "reference" method).…”

Section: Radiation-grafted (Rg) Membranesmentioning

confidence: 99%

An optimised synthesis of high performance radiation-grafted anion-exchange membranes

et al. 2017

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High performance benzyltrimethylammonium-type alkaline anion-exchange membranes (AEM), for application in electrochemical devices such as anion-exchange membrane fuel cells (AEMFC), were prepared by the radiation grafting (RG) of vinylbenzyl chloride (VBC) onto 25 μm thick poly(ethylene-co-tetrafluoroethylene) (ETFE) films followed by amination with trimethylamine. Reductions in electron-beam absorbed dose and amount of expensive, potentially hazardous VBC were achieved by using water as a diluent (reduced to 30 – 40 kGy absorbed dose and 5%vol VBC) instead of the prior-art method that used organic propan-2-ol diluent (required 70 kGy dose and 20%vol VBC monomer). Furthermore, the water from the aqueous grafting mixture was easily separated from residual monomer (after cooling) and was reused for a further grafting reaction: the resulting AEM exhibited an ion-exchange capacity of 2.1 mmol g-1 (cf. 2.1 mmol g-1 for the AEM made using fresh grafting mixture). The lower irradiation doses resulted in mechanically stronger RG-AEMs compared to the reference RG-AEM synthesised using the prior-art method. A further positive off-shoot of the optimisation process was the discovery that using water as a diluent resulted in an enhanced (i.e. more uniform) distribution of VBC grafts as proven by Raman microscopy and corroborated using EDX analysis: this led to enhancement in the Cl- anion-conductivities (up to 68 mS cm-1 at 80°C for the optimised fully hydrated RG-AEMs vs. 48 mS cm-1 for the prior-art RG-AEM reference). A down-selected RG-AEM of ion-exchange capacity = 2.0 mmol g-1, that was synthesised using the new greener protocol with 30 kGy electron-beam absorbed dose, led to an exceptional beginning-of-life H2/O2 AEMFC peak power density of 1.16 W cm−2 at 60°C in a benchmark test using industrial standard Pt-based electrocatalysts and unpressurised gas supplies: this was higher than the 0.91 W cm-1 obtained with the reference RG-AEM (IEC = 1.8 mmol g-1) synthesised using the prior-art protocol

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Section: Radiation-grafted (Rg) Membranesmentioning

confidence: 99%

An optimised synthesis of high performance radiation-grafted anion-exchange membranes

et al. 2017

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“…This situation changed in 2016 after the development of a new grafting protocol, 24 involving an emulsion method for peroxidation graft polymerisation of VBC onto ETFE film using water as a diluent, which significantly enhanced the DoG compared to the previous use of propan-2-ol as an organic diluent. 25 This had many benefits: (1) lower radiation absorbed doses could be used, which was important when partially-fluorinated precursor films were being used;…”

Section: Introductionmentioning

confidence: 99%

Non-fluorinated pre-irradiation-grafted (peroxidated) LDPE-based anion-exchange membranes with high performance and stability

Wang

Brink

Liu

et al. 2017

Energy Environ. Sci.

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“…AEM development has focused on controlling the membrane morphology and functionalization with various cationic groups in an attempt to attain excellent thermal and mechanical properties along with improved hydroxide conductivity (≥0.1 S cm −1 ) [51]. Most of the developed AEMs were employed in fuel cell applications [25,26,30,32,35,40,[42][43][44][45]47], with only a few AEMs used in water electrolysis cell tests [21,50]. The AEMs used in fuel-cell applications can also be used in water electrolysis applications.…”

Section: Introductionmentioning

confidence: 99%

A Review on Membranes and Catalysts for Anion Exchange Membrane Water Electrolysis Single Cells

Cho

Lim

Lee

et al. 2017

J. Electrochem. Sci. Technol

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The research efforts directed at advancing water electrolysis technology continue to intensify together with the increasing interest in hydrogen as an alternative source of energy to fossil fuels. Among the various water electrolysis systems reported to date, systems employing a solid polymer electrolyte membrane are known to display both improved safety and efficiency as a result of enhanced separation of products: hydrogen and oxygen. Conducting water electrolysis in an alkaline medium lowers the system cost by allowing non-platinum group metals to be used as catalysts for the complex multi-electron transfer reactions involved in water electrolysis, namely the hydrogen and oxygen evolution reactions (HER and OER, respectively). We briefly review the anion exchange membranes (AEMs) and electrocatalysts developed and applied thus far in alkaline AEM water electrolysis (AEMWE) devices. Testing the developed components in AEMWE cells is a key step in maximizing the device performance since cell performance depends strongly on the structure of the electrodes containing the HER and OER catalysts and the polymer membrane under specific cell operating conditions. In this review, we discuss the properties of reported AEMs that have been used to fabricate membrane-electrode assemblies for AEMWE cells, including membranes based on polysulfone, poly(2,6-dimethyl-p-phylene) oxide, polybenzimidazole, and inorganic composite materials. The activities and stabilities of tertiary metal oxides, metal carbon composites, and ultra-low Pt-loading electrodes toward OER and HER in AEMWE cells are also described.

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Reduction of the monomer quantities required for the preparation of radiation-grafted alkaline anion-exchange membranes

Cited by 18 publications

References 34 publications

An optimised synthesis of high performance radiation-grafted anion-exchange membranes

An optimised synthesis of high performance radiation-grafted anion-exchange membranes

Non-fluorinated pre-irradiation-grafted (peroxidated) LDPE-based anion-exchange membranes with high performance and stability

A Review on Membranes and Catalysts for Anion Exchange Membrane Water Electrolysis Single Cells

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