2017
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2016
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- Reviews of our paper "The anion effect on Li+ ion coordination structure in ethylene carbonate solutions" published on J. Phys. Chem. Lett. has appeared on MINA-News (pdf) and on the CEA Direction de la Recherche Fondamentale web site (pdf)
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abstract
Hydrated perfluoro-sulfonic acid polymers used as separators in fuel cells form phase-separated morphologies that show outstanding proton-conducting properties. These are directly related to the state and dynamics of the adsorbed water molecules. We have quantified water motions and ion transport in these materials by combining Quasi Elastic Neutron Scattering, Pulsed Field Gradient NMR and Molecular Dynamics computer simulation. We have determined effective water and ion diffusion coefficients at the relevant molecular, nano- and meso- scales, together with their variation upon hydration. We demonstrate that the mobility of species is controlled by the balance between short range interactions and connectivity. We show that confinement at the nano-scale and direct interaction with the interfaces produce anomalous sub-diffusion within the ionic nano-channels, independently from the details of the chemical architecture of the hydrophobic matrix. We elucidate the true nature of water confined in soft nano-structures and provide a general understanding of the complex multi-scale structure-function interplay in advanced materials. |