Noninvasive Experimental Evidence of the Linear Pore Size Dependence of Water Diffusion in Nanoconfinement

作者:Chemmi Houria; Petit Dominique*; Levitz Pierre; Denoyel Renaud; Galarneau Anne; Korb Jean Pierre
来源:Journal of Physical Chemistry Letters, 2016, 7(3): 393-398.
DOI:10.1021/acs.jpclett.5b02718

摘要

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.

  • 出版日期2016-2-4