Continuous ultrafiltration of reverse micelles in the ternary system Igepal CA 520/cyclohexane/water

Abstract

Abstract The ultrafiltration is a separation technique at the nanometer scale and is applicable for the rejection of reverse micelles, spherical aggregates of surfactants, at membrane surfaces. We investigated the continuous ultrafiltration of reverse micelles in the non‐ionic ternary system Igepal CA 520/cyclohexane/water. The dependence of flux velocity and rejection on transmembrane pressure, droplet size, concentration of surfactant and temperature is described. With increasing pressure we also found micelles beside surfactant monomers in the permeate. This effect is observed more strongly when using non‐ionic surfactants than using ionic surfactants. It is discussed on the basis of the flexibility of the micelles. The results of the ultrafiltration process are compared with theoretical models, which are developed for the ultrafiltration of macromolecules from aqueous solutions: the gel layer models, which are developed for the ultrafiltration of macromolecules from aqueous solutions: the gel layer model, the model of osmotic pressure and the force balance model.