Molecular diffusion in disordered interfacial media as probed by pulsed field gradients and nuclear magnetic relaxation dispersion

We address the question of probing the fluid dynamics in disordered interfa cial media by Pulsed field gradient (PFG) and Magnetic relaxation dispersio n (MRD) techniques. We show that the PFG method is useful to separate the e ffects of morphology from the connectivity in disordered macroporous media. We propose simulations of molecular dynamics and spectral density function s, J(omega), in a reconstructed mesoporous medium for different limiting co nditions at the pore surface. An algebraic form is found for J(omega) in pr esence of a surface diffusion and a local exploration of the pore network. A logarithmic form of J(omega) is found in presence of a pure surface diffu sion. We present magnetic relaxation dispersion experiments (MRD) for water and acetone in calibrated mesoporous media to support the main results of our simulations and theories.