Membranes as fractals: Implication and consequences

Abstract

The fractal nature of synthetic membranes suggests a new approach to implement pore size distributions in membrane characterization. The fractal definition of membrane morphology implies that the pore size distribution of a synthetic membrane can be described by a set of three parameters such as the minimum and maximum pore radius and the fractal dimension D. The effect of such a pore size distribution on solute sieving curves has been determined parametrically for the permeation of dilute aqueous solutions of polyethylene glycols through ultrafiltration membranes. These results have been compared to sieving curves obtained from the normal and log-normal pore size distributions which represent the conventional approach in defining the porosity of synthetic membranes.