Creaming Behavior of Solids-Stabilized Oil-in-Water Emulsions

Creaming behavior of oil-in-water emulsions stabilized by kaolinite clays was studied. The clays were treated with asphaltenes resulting in clays having different contact angles. It was found that the emulsion creaming velocity decreased and that the volume of the creamed emulsions increased with increasing clay concentration at the oil droplet surface. At a given initial clay concentration in the aqueous phase, a plot of the emulsion creaming velocity versus the square of the oil droplet diameter did not follow any rational hindered settling equation. At a constant clay concentration at the oil droplet surface, however, a plot of the emulsion creaming velocity versus the square of the effective oil droplet diameter gave a straight line passing through the origin. A model for creaming of solids-stabilized oil-in-water emulsions was developed, and it is able to predict the creaming velocity of the emulsions quite well.