Rheology of emulsions stabilized by solid interfaces

The rheological behavior of soybean oil emulsions stabilized by sodium caseinate is studied. While having a very low interfacial tension, these emulsions, when concentrated up to an oil volume fraction of 64%, have a very high elasticity. It is 30 times higher than those usually observed for surfactant-stabilized emulsions. We show that this high elasticity originates from the interfacial shear elasticity of the bilayer interface. So, sodium caseinate stabilized droplets can be regarded as droplets coated with a solid shell.