ULTRASONIC WAVE-PROPAGATION IN COLLOID SUSPENSIONS AND EMULSIONS - RECENT EXPERIMENTAL RESULTS

Early theories of acoustic propagation such as those by Urick, and Uri ck and Ament, are attractive because bf their computational simplicity , but limited in application. The more complex models of Allegra and H awley, and Harker and Temple, have since gained application. A wideban d ultrasonic attenuation and phase velocity spectrometer have been use d to determine the validity of these models for a range of colloidal m aterials. Measurements taken validate the Allegra and Hawley model for colloids with spherical base particles. The Harker and Temple model i s used to infer changes in the flocculation state of kaolin slurries w hich result from chemical intervention.