Abstract: The permeation and entrainment swelling in W/O/W emulsions were studied in the batch stirrers experimentally. The results show that the permeation swelling increases with increasing the osmotic pressure difference between the internal and the external phases as well as the concentration of the surfactants and the carriers in the membranes, but decreases with increasing the membrane viscosity. When the osmotic pressure difference is higher, the effect of the water permeation on swelling is larger than that of the entrainment. The effect of the oxygen-containing compounds in the membranes on swelling is larger than that of the nitrogen-containing compounds. When span 80 was used as the surfactant, the permeation swelling was 6 times higher than when E644 was used, and the entrainment swelling was also higher. Repeated of coalescence and redispersion can promote the swelling caused by the entrainment. From these results, it is concluded that the multistage mixer-settler seems unsuitable to the liquid membrane, operations.

Key words: Liquid membrane, W/O/W emulsion, W/O emulsion, Permeation swelling, Entrainment swelling