Isotonic swelling behavior of W/O/W emulsion liquid membranes under agitation conditions

A new on-line technique is developed to continuously monitor the isotonic swelling behavior of water-in-oil-in-water (W/O/W) emulsion liquid membranes (ELMs) under agitation condition. The technique is based on electrical conductivity measurement. The effects of surfactant concentration, initial volume fraction of dispersed globules, and stirring speed on the swelling profiles of W/O/W ELMs are determined using the new on-line technique. With the increases in the stirring speed and initial volume fraction of dispersed-phase, the swelling rate increases. With the increase in the surfactant concentration, a more complicated behavior is observed—the swelling rate increases initially, reaches a maximum value and then falls off with further increase in the surfactant concentration. Under certain conditions, phase inversion of multiple W/O/W emulsion to simple W/O emulsion is observed.