Eur. Phys. J. AP 5, 127-134 (1999)
https://doi.org/10.1051/epjap:1999120

Ultrasonic attenuation spectroscopy and light scattering study of the ageing of very fine emulsions

¹ Biopolymers and Colloids Research Laboratory, Department of Food Science, University of Massachusetts, Amherst, MA 01003, USA
² Laboratoire de Dynamique des Fluides Complexes, Université Louis Pasteur, 4 rue Blaise Pascal, 67000 Strasbourg, France

Received: 6 August 1998
Revised: 28 October 1998
Accepted: 28 October 1998
Published online: 15 February 1999

Abstract

Very fine, 10% vol/vol, n-hexadecane and n-octadecane oil-in-water emulsions, stabilized by sodium dodecyl sulfate, have been prepared. Due to the very small size of the oil droplets, these emulsions are susceptible to undergo Ostwald ripening and/or coalescence. The maturation of the emulsions was studied over several months by three different techniques: ultrasonic attenuation spectroscopy, static light scattering and dynamic light scattering. Ultrasonic spectroscopy measurements between 0.5 and 10 MHz appeared as the most convenient technique for monitoring the changes in the size of such droplets. Moreover, the correlation of the results from the three different techniques allows a complete determination of the particle size and polydispersity during the ageing.