Effect of Compositional Changes on the Viscosity of Low Internal Phase Emulsions

Low internal phase emulsions (LIPE) have extensive industrial applications. These emulsions contain apart from oil/water, and emulsifier many additives such as co-emulsifiers, active ingredients, electrolytes and perfumes. An attempt is made in this study to investigate the influence of a variety of compositional parameters and additives on a typical LIPE. The viscosity of the emulsion increases with the melting point of the oil phase. There was a small increase in viscosity with increase of emulsifier concentration from 1 to 2 percent, followed by a steep increase in viscosity above 2 percent. The effect of sodium chloride addition on the viscosity of the emulsion depended on the stage of addition. Organic additives either decreased or had little effect on the viscosity depending on their polarity. These results have been explained on the basis of properties of the film formed at the oil/water interface.