ANALYSIS OF TRANSPORT PHENOMENA IN CELLULOSE DIACETATE MEMBRANES .1. RELATION BETWEEN DIALYSIS COEFFICIENTS AND MEMBRANE MORPHOLOGY AND HYDRATION

Transport properties were determined for various Loeb‐type membranes which exhibit strong structure differences from one to another. Using linear relations of thermodynamics of irreversible processes for the homogeneous ones, correlations were found between the specific transport coefficients and the states of water in the membrane medium. In the case of heterogeneous membranes a schematic multilayer model, using in an appropriate way Darcy's law, was worked out in accordance with electron micrographs of membrane cross sections. It enables us to correlate the membrane hydraulic permeability with the relative extent of four typical structures A, B, C, and D. In addition, this model provides both the hydraulic specific permeabilities of these types of structure and their hydration characteristics. Copyright © 1979 John Wiley & Sons, Inc.