Translational diffusion of liquids at surface of microporous materials: new theoretical analysis of field cycling magnetic relaxation measurements

1H spin-lattice relaxation rates of several aprotic polar liquids on calibrated microporous chromatographic glass beads that have paramagnetic ion impurities are recorded over magnetic field strengths using a field-switched magnetic relaxation dispersion spectrometer. The typical bilogarithmic magnetic field dependence of these rates supports quantitatively our theory of nuclear paramagnetic relaxation and gives the translational diffusion at the surface of nanopores. Our results demonstrate that magnetic relaxation dispersion at low magnetic field strengths in high surface area heterogeneous systems may be quantitatively understood in terms of the parameters of the spatial confinement and the local translational dynamics.