Separation and Fractionation of Macromolecular Solutions by Ultrafiltration

Abstract

Abstract The present state-of-the-art of membrane ultrafiltration with reference to macromolecular fractionations is reviewed. Ultrafiltration is now a widely used technique, both in the laboratory and industrial applications, which stems from the development of asymmetric membranes followed by the recognition of the importance of fluid mechanical and mass transfer processes and their management through equipment design and fluid-flow practices. However, large-scale fractionation of macromolecular mixtures or solutions such as proteins has not yet been feasible. This inability is attributable to a number of factors, viz., concentration polarization and fouling processes which may also be coupled with limitations imposed by nonuniform pore size as well as protein–protein (solute) interactions, the latter being determined by the solution chemistry. It is now well recognized that boundary-layer and interfacial effects, in general, are extremely important in membrane applications, as evidenced by a number of ...