Diffusion in porous materials above the percolation threshold.
The diffusion of water-soluble solutes in water-soaked porous media was studied by following the release of benzoic acid from poly(vinyl stearate) matrices. The results were analyzed using a pseudo-steady-state diffusion model coupled with the fundamental concepts of percolation theory. The results of the study indicated that the relationship between the bulk diffusion coefficient of benzoic acid in the polymer matrix and the porosity was well described by percolation scaling laws. A very low percolation threshold (0.07) was experimentally observed for this system.
Hastedt
J E
JE
University of Wisconsin, School of Pharmacy, Madison 53706.
Wright
J L
JL
D001565:Benzoates; D019817:Benzoic Acid; D003692:Delayed-Action Preparations; D004058:Diffusion; D008962:Models, Theoretical; D010316:Particle Size; D011108:Polymers / Q000378:metabolism*; D012995:Solubility
D001565:Benzoates; D003692:Delayed-Action Preparations; D011108:Polymers; D019817:Benzoic Acid