Effect of organic solvents on stability of liquid surfactant membranes

Abstract

The effect of osmotic pressure gradient on the stabilities of various liquid surfactant membranes (LSMs) consisting of organic solvents was studied in terms of the change in water content of (W/O) emulsions and the breakdown ratio of the liquid membrane. No water permeation into (W/O) droplets through the membrane was observed under isotonic conditions; the entrainment of external aqueous phase was suppressed in the presence of electrolytes in the continuous phase. A greater osmotic pressure gradient brings about larger changes in the water content and membrane breakdown. A liquid membrane consisting of aliphatic hydrocarbons becomes more stable with increasing number of carbon atoms, while one consisting of toluene has very low mechanical strength. The value of the water permeation coefficient was found to be in the range from 2.9 × 10-7 to 1.5 × 10-6 m/s. © 1989, The Society of Chemical Engineers, Japan. All rights reserved.