Abstract
In this study, two oil-water systems of oleic acid-water and chloroform-water were used as sample. The ultrasound was sequentially irradiated by using five ultrasonic transducers at 20 kHz, 0.5 MHz, 1.6 MHz, 2.4 MHz and 4.8 MHz to produce emulsion. The distribution of droplet diameter was measured. The effects of ultrasonic frequency and oil kind on the emulsion characteristics were experimentally examined. For the oleic acid-water system, the droplet diameter decreased and the stability of emulsion increased as the step number and the frequency of tandem acoustic emulsification increased. The emulsion formed by tandem acoustic emulsification at 4.8 MHz was still stable after 7 months. The stability of emulsion decreased with increasing oil volume raction. For the chloroform-water system, the diameter and polydispersity of droplet became drastically small by tandem acoustic emulsification. Compared with oleic acid-water system, the stability of emulsion was low.
