Poly(arylene ether sulfone)s with densely located ionic groups for alkaline fuel cells

Författare

Patric Jannasch
Annika Weiber

Summary, in English

Proton-exchange membrane fuel cells (PEMFCs) have been widely studied in the search for alternative power sources. However, there are still several challenges remaining with this technology linked to high costs and life-time issues.1 One alternative to the use of PEMFCs

is to explore the prospects of alkaline membrane fuel cells (AMFCs). This type of fuel cell has more favorable reaction kinetics, and can thus be utilized with lower amounts of, or even without, the expensive catalysts upon which PEMFCs rely.2 Still, in order to develop AMFCs which can be used commercially, substantial improvements of the anion exchange membrane(AEM) are needed. The alkaline environment and the low tendency of the cationic groups

to aggregate make the macromolecular design crucial. We have previously found that the transport properties of PEMFC membranes can be significantly enhanced by concentrating the anionic groups on specific chain segments in the polymer backbone.3,4

In the presented work we have investigated how the distribution of the cationic groups along the polymer backbone affects the transport properties of AEMs. By incorporating methylated hydroquinones into poly(arylene ether sulfone)s it was possible to selectively place

either two, three or four ionic groups on single phenylene rings in the polymer backbone. With this methodology we were able to carefully control and vary the ion distribution along the

polymer backbone. Properties such as water uptake and ion conductivity of the AEMs were studied alongside with small angle X-ray scattering in order to establish correlations between

molecular structure, membrane morphology and ion conductivity.

1. Park, C.H. Lee, C.H., Guiver, M.D., and Lee, Y.M. (2011), Prog. Polym. Sci., 36, 1443-1498.

2. Hickner, M.A., Herring, A.M., and Coughlin, E.B. (2013), 51, 1727-1735.

3. Weiber, E.A., Takamuku, S., and Jannasch, P. (2013, Macromolecules, 46, 3476-3485.

4. Takamuku, S., Weiber, E.A., and Jannasch, P. (2013), ChemSusChem, 6, 308-319.

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