Flow and transport studies in (non)consolidated porous (bio)systems consisting of solid or porous beads by PFG NMR

Displacement imaging pulsed field gradient nuclear magnetic resonance (PFG NMR) is applied to a number of porous model systems, consisting of either solid or porous particles, By pulsed field gradient nuclear magnetic resonance, the molecular displacement can be measured that occurs during a time interval, Delta, between two consecutive magnetic field gradient pulses. In contrast to conventional techniques, which cover displacements over distances several times the bead diameter, pulsed field gradient nuclear magnetic resonance covers displacements in the order of subpore to several pore distances. Dimensionless scaling is possible based on the root-mean-square displacement normalised on the bead diameter. In solid particles, v and Delta are interchangeable, although different flow regimens are covered. In porous particles, the exchange time between the stagnant mobile phase in the particles and the flowing outside must be taken into account with respect to Delta as well as the porosity. (C) 1998 Elsevier Science Inc.