Evaluation of Emulsifier Blending by the Measurement of Phase Inversion Temperature of the Emulsion

Abstract

The effect of emulsifier blending on the hydrophile-lipophile balance of the mixture was studied by measuring the phase inversion temperature (PIT, HLB-temperature). The effective pair of emulsifiers was also investigated by determining the emulsion properties such as size distribution and stability.
The following results were obtained. 1) When the difference of the HLB of emulsifiers to be blended was small, the emulsifier mixture showed the weight average HLB number of the emulsifiers and expected emulsifying performances were obtained, and 2) when the difference of the HLB numbers of emulsifiers to be blended was large, the observed HLB number of the mixture was not their weight average number and the mixture gave a less stable emulsion. It is clear from the present result that an emulsifier which has moderate solubility behavior towards water and oil is necessary in addition to hydrophilic or lipophilic emulsifiers in order to stabilize emulsions in a wide range of HLB-temperatures.