Separation of aqueous solutions of nonionic organic solutes by ultrafiltration

Abstract

A study has been made of the conformity to natural laws of ultrafiltration separation of aqueous solutions of nonionic organic solutes with molecular weights ranging from 90 to 40,000 daltons (glycerol, glucose, sucrose, and poly (ethylene glycol)s of various molecular weights) on cellulose acetate and poly (sulfonamide) ultrafiltration membranes [UAM and UPM series (Vladipor)] as well as nuclear poly (ethylene terephthalate) membrane filters. It was shown that the corresponding experimental data are described correctly in terms of the fine porous membrane model (for low values of pressure and concentration) and the concentration polarization-gel formation model (for high molecular weight solutes and elevated pressures and concentrations). The effects of the macromolecular chain deformation and orientation must be taken into account in the interpretation of the experimental dependences. The dependences established permit valuable information to be obtained about the conditions of calibration (characterization) of ultrafiltration membranes and their practical application for polydisperse system fractionation.