A Magnetic Characterization Of The Texture Of Simple Porous-media

A novel, magnetic way of characterizing the geometric structure of the voids in macroporous material is presented. A system of methane gas confined interstitially in a close-packed assembly of non-absorbent zirconia beads constitutes a two-phase model (pore and matrix) of simple porous media. Nuclear magnetic resonance measurements of the proton spectral linewidth and spin echo decay are reported. They are compared with a theoretical model of the intrinsic, non-uniform, magnetic field and its gradient, which are due to the heterogeneous magnetic susceptibility. Three magnetic parameters are derived, which indirectly characterize the pore geometry and which adequately describe the system over seven-ford ranges of gas pressure and bead size.