Anhydrous proton conduction in self-assembled and disassembled ionic molecules
In polymer based ionic conductors, the conductivity is suppressed by a low degree of chain mobility, therefore it is imperative to design a molecular system in which ionic groups can be mobilized and immobilized as a function of temperature to allow ions to move freely as well as in a controlled man...
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Veröffentlicht in: | Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2018-01, Vol.6 (14), p.674-684 |
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Hauptverfasser: | , , , , |
Format: | Artikel |
Sprache: | eng |
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Zusammenfassung: | In polymer based ionic conductors, the conductivity is suppressed by a low degree of chain mobility, therefore it is imperative to design a molecular system in which ionic groups can be mobilized and immobilized as a function of temperature to allow ions to move freely as well as in a controlled manner with a low energy barrier. Herein, we report an innovative approach to combine both the concepts of self-assembly and disassembly of the functionalized molecules to investigate anhydrous ionic (proton) conduction and related activation energy (
E
a
). For this purpose, organic proton conductors are designed in such a way that self-assembly of the molecules can occur
via
non-covalent interactions giving rise to an organized solid state in which ionic groups are held together
via
a network of hydrogen bonds. A new class of anhydrous ionic conductors with hydrophobic and hydrophilic counterparts namely alkyl chains and a phosphonic acid group, respectively, are investigated for fuel cell applications. The highest anhydrous proton conductivity of up to 10
−2
S cm
−1
at 140 °C is recorded for these ionic molecules. Thermal gravimetric analysis of these materials demonstrates their stability up to 190 °C and thereby their ability to perform at high temperature.
The phenomenon of self-assembly and disassembly was employed to investigate the proton conduction in organic phosphonic acids decorated with lyophilic hydrocarbon chains. |
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ISSN: | 2050-7488 2050-7496 |
DOI: | 10.1039/c8ta00390d |