A novel system was employed to determine the aggregation behaviour of emulsion droplets in situ while sheared in a rheometer. Tetradecane (15% v/v) emulsions stabilized with 1% sodium caseinate were sheared at various shear rates up to 1000 1/s using a rheometer.  The light scattering signal was measured, undiluted using a backscattering geometry. Changes in the viscosity of the emulsions were measured in parallel to light scattering. The colloidal properties after shear were also measured using transmission diffusing wave spectroscopy (with no dilution) and conventional light scatttering (after extensive dilution). The set up clearly showed the differences in the flocculation behaviour of the emulsions, induced by addition of calcium or small molecular weight emulsifier, Tween 20. The results demonstrated how measuring changes in situ may help in fine tuning formulations and processes to obtain optimal stability.

In situ light scattering of shear induced destabilization of  emulsion droplets

245th National Meeting (2013)

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