The viscoelastic properties of a soap-stabilized oil-in-water emulsion

The viscoelastic properties of dilute flocculated paraffin oil-in-water emulsions stabilized by 5% potassium laurate have been measured using a method based on oscillatory flow in small tubes. Viscosity and elasticity were found to increase exponentially with volume fraction of dispersed oil. The ratio of the elastic energy storage to viscous energy dissipation at 2 Hz shows a maximum for an oil volume fraction of 0.2, the relaxation time for the emulsion under these conditions being 0.08 sec. An estimate of the strength of the forces which hold the emulsion particles together has been obtained from oscillatory measurements at large amplitudes. The results are discussed in terms of the known relations between colloid stability and rheological properties. 17 references.