MODIFICATION OF ULTRAFILTRATION MEMBRANES BY DEPOSITION OF COLLOID PARTICLES

We describe an experimental procedure for the modification of ultrafil tration membranes by the deposition of monodisperse polymer spheres. T he conditions for irreversible formation of particulate deposit are st udied and correlated with the particle charge. The separation characte ristics of the membranes before and after particle deposition are comp ared. For this purpose, a method for determining the membrane rejectio n coefficient is developed. The method is based on the light-scatterin g study of permeates obtained upon the filtration of commercial dextra n samples. The results show that the modified membranes have improved retention characteristics. (C) 1998 Elsevier Science B.V.