Porous polycarbonate phase-inversion membranes

This paper presents a method of preparation of phase-inversion porous polycarbonate membranes as well as experimental data on their structure and transport and separation properties. From a casting solution containing 8% of polycarbonate in a mixture of dioxane and dimethylformamide (mass ratio 3: 2), it is possible to obtain porous membranes by the phase-inversion method. Gelation should be carried out in an atmosphere of air saturated with water vapour. The porosity of the membranes can be controlled by the time and temperature of gelation. The obtained membranes are reasonably symmetrical, having a spongy structure with identical pore sizes and a skinned external structure. They retain macromolecules and suspended substances to a degree which depends on the nature of the solutes and on the pressure.