Effect of surfactant addition on the morphology and pervaporation performance of asymmetric polysulfone membranes

In the present work, the separation of aqueous alcohol solution through wet-phase inversion prepared polysulfone (PSf) membrane was investigated by using the pervaporation process. The role played by surfactant (Span-80) in the formation of PSf membrane was also studied. Addition of surfactant in the casting solution can suppress macrovoids in polymeric membrane. The formation of asymmetric PSf membranes was discussed in terms of the presence of surfactant in the casting solution and the PSf concentration. The surface properties of the asymmetric PSf membranes were characterized by scanning electron microscopy (SEM). The effects of polymer concentration, surfactant content, feed composition, and feed solution temperature on the pervaporation performance were investigated. The separation factor towards water and the permeation rate for a 10 wt.% aqueous ethanol solution through the asymmetric PSf membrane with a 15 wt.% Span-80 were 16 and 240 g/m(2) h, respectively. (C) 2000 Elsevier Science B.V. All rights reserved.