Donnan-steric-pore model

Schaep, J., Vandecasteele, C., Mohammad, A.W., and Bowen, W.R., Analysis of the salt retention of nanofiltration membranes using the Donnan-steric partitioning pore model, Separ. Purif. Technol, 34 (15), 3009-3030, 1999. 

Transport through nanofiltration membranes is controlled primarily by electrostatic and steric interactions. The extended Nemst-Plank equation commonly is used with Donnan and steric partitioning to predict transport rates based on effective membrane charge density, pore radius, and thickness to porosity ratio [131-132]. Inclusion of solute-pore hydrodynamic interactions and a pore size distribution improves the predictive and correlative capabilities of the models [133]. 

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