Rheology of Highly Flocculated Oil in Water Emulsions

The viscous flow behavior of highly flocculated oil in water emulsions was studied experimentally using a co-axial cylinder viscometer. The aqueous phase of the emulsions consisted of a non-Newtonian solution of Carbopol-940 in tap water; the oil phase consisted of a Newtonian white mineral oil. The emulsions produced were very viscous and they appeared “gelled”. The shear stress/shear rate behavior of the emulsions was described by the Casson's model. The yield-stress in emulsions was found to depend upon the concentrations of the dispersed phase (oil) and the polymer. The yield-stress increased non-linearly with the dispersed phase concentration and it increased linearly with the polymer concentration