Proton Transport in Electrospun Hybrid Organic–Inorganic Membranes: An Illuminating Paradox |
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Authors: | Leslie Dos Santos Manuel Maréchal Armel Guillermo Sandrine Lyonnard Simona Moldovan Ovidiu Ersen Ozlem Sel Hubert Perrot Christel Laberty‐Robert |
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Affiliation: | 1. Sorbonne Université, UPMC Univ. Paris 06, CNRS UMR 7574, Collège de France, Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), Paris, France;2. CNRS, INAC‐SPRAM, Grenoble, France;3. Univ. Grenoble Alpes, INAC‐SPRAM, Grenoble, France;4. CEA, INAC‐SPRAM, Grenoble, France;5. Institut de Physique et Chimie des Matériaux des Strasbourg, IPCMS, CNRS UMR 7504, Strasbourg 02, France;6. Sorbonne Université, UPMC Univ Paris 06, CNRS UMR 8235, Laboratoire Interfaces et Systèmes Electrochimiques, Paris, France |
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Abstract: | Chemistry and processing have to be judiciously combined to structure the membranes at various length scales to achieve efficient properties for polymer electrolyte membrane fuel cell to make it competitive for transport. Characterizing the proton transport at various length and space scales and understanding the interplays between the nanostructuration, the confinement effect, the interactions, and connectivity are consequently needed. The goal here is to study the proton transport in multiscale, electrospun hybrid membranes (EHMs) at length scales ranging from molecular to macroscopic by using complementary techniques, i.e., electrochemical impedance spectroscopy, pulsed field gradient‐NMR spectroscopy, and quasielastic neutron scattering. Highly conductive hybrid membranes (EHMs) are produced and their performances are rationalized taken into account the balances existing between local interaction driven mobility and large‐scale connectivity effects. It is found that the water diffusion coefficient can be locally decreased (2 × 10?6 cm2 s?1) due to weak interactions with the silica network, but the macroscopic diffusion coefficient is still high (9.6 × 10?6 cm2 s?1). These results highlight that EHMs have slow dynamics at the local scale without being detrimental for long‐range proton transport. This is possible through the nanostructuration of the membranes, controlled via processing and chemistry. |
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Keywords: | diffusion coefficients electrospun membranes hybrid membranes multiscales multitechniques |
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