THEORETICAL ASPECTS OF THE ESTIMATION OF PORE AND MASS FRACTAL DIMENSIONS OF POROUS-MEDIA ON THE MACROSCOPIC SCALE USING NMR IMAGING

NMR imaging studies, employing spin density and spin-lattice relaxatio n lime (T-1) contrasted images, have been used in the past to probe th e spatial variation of voidage and pore size in porous materials such as porous catalyst support pellets. A method has been suggested to est imate the values of the mass and pore fractal dimensions of the struct ures underlying NMR spin density images. The method has been tested on simulated images of model structures of known geometry and shown to b e a successful probe of the nature of the structure underlying an imag e. This method is suggested as a way of selecting a suitable model to simulate the structural properties of real porous materials over lengt h scales from 0.01-10 mm. (C) 1998 Elsevier Science Ltd. All rights re served.