An Attempt at Measuring the Stability of W/O/W-type Multiple-Phase Emulsions by Analyzing the Concentration of Ions

Abstract

An attempt was carried out to provide a new method for evaluating the stability of W/O/Wtype multiple-phase emulsions by using a technique for analyzing the concentration of ions, which migrated from the inner aqueous-phase to the aqueous suspending medium due to the rupture of oil phase layer on the surface of the inner aqueous-phase globules. The following is the procedure tested; a newly prepared sample cantaining a small amount of sodium chloride in the inner aqueous-phase is dialyzed against a definite volume of distilled water, in which a pair of ion-electrodes is immersed to detect continuously the amount of either the sodium ions or chloride ions which migrated from the inner aqueous-phase through the aqueous suspending medium. Percentage of the alived inner aqueous globules in the sample at optional time was calculated by the relations;where A and B are the ion concentrations in the distilled water and in the inner aqueous-phase, respectively, x (ml) is the volume of leaked inner aqueous-phase and v1, v0 and vd are the volumes of the inner aqueous-phase, outer aqueous-phase and distilled water of the dialyzing system, respectively.It has been confirmed that the method proposed here is useful for examining the stability of W/O/W-type multiple-phase emulsions under the various conditions.