Design and Application of a Low-Molecular-Mass Cut-Off Poly (Ether Sulphone) Membrane

Low-molecular-mass cut-off tubular ultrafiltration membranes have been developed at the Institute for Polymer Science at the University of Stellenbosch; the compositions and the manufacturing methods are such that these membranes can be made commercially on an industrial scale. Three membranes were designed which gave performances comparable to those of other commercial membranes. The development work comprised detailed studies of the mechanisms of the phase-inversion process, of the solvents and non-solvents used in the gelation step, and of the factors influencing the actual physical production of the membranes. The technology of producing the membranes was successfully transferred to the commercial-scale operation and the membranes have been shown to be economically productive and to show promise in removing colour contamination from natural surface waters and from process streams in the sugar industry.