title: Noninvasive Experimental Evidence of the Linear Pore Size Dependence of Water Diffusion in Nanoconfinement.
abstract: We show that nuclear magnetic relaxation experiments at variable magnetic fields (NMRD) provide noninvasive means for probing the spatial dependence of liquid diffusion close to solid interfaces. These experiments performed on samples of cylindrical and spherical nanopore geometries demonstrate that the average diffusion coefficient parallel to the interface is proportional to the pore radii in different dynamics regimes. A master curve method allows extraction of gradients of diffusion coefficients in proximity of the pore surfaces, indicative of the efficiency of coupling between liquid layers. Due to their selectivity in frequency, NMRD experiments are able to differentiate the different water dynamical events induced by heterogeneous surfaces or composed dynamical processes. This analysis relevant in physical and biological confinements highlights the interplay between the molecular and continuous description of fluid dynamics near interfaces.
authors.affiliation: Physique de la Matière Condensée, Ecole Polytechnique-CNRS , Palaiseau 91128, France.
authors.forename: Houria
authors.initials: H
authors.lastname: Chemmi
authors.affiliation: Physique de la Matière Condensée, Ecole Polytechnique-CNRS , Palaiseau 91128, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Petit
authors.affiliation: Physicochimie des Electrolytes et Nanosystèmes Interfaciaux, CNRS-UMR 8234, Université Pierre et Marie Curie , 4 place Jussieu, 72522 Paris Cedex 5, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Levitz
authors.affiliation: MADIREL, Aix-Marseille Université, CNRS-UMR 7246 , Centre de St Jérôme, 13397 Marseille Cedex 20, France.
authors.forename: Renaud
authors.initials: R
authors.lastname: Denoyel
authors.affiliation: Institut Charles Gerhardt Montpellier, UMR 5253 CNRS-UM-ENSCM, ENSCM , 8 rue de l'Ecole Normale, 34296, Montpellier Cedex 05, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Galarneau
authors.affiliation: Physique de la Matière Condensée, Ecole Polytechnique-CNRS , Palaiseau 91128, France.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Korb