Effect of piezoelectric transducer material type on ultrasound assisted coalescence of water-in-oil emulsion

Abstract

The usage of lead zirconate titanate poses serious health and environmental hazards. The production or utilization of PZTs results in the release of vaporized hazardous lead oxide (PbO) at elevated temperature or dissolution of poisonous lead into aqueous medium. Hence, in this study, the analysis of the effect of different piezoelectric material type (PZT, PVDF and Lithium Niobate) on domain acoustic pressure distribution and the subsequent coalescence of binary droplets was conducted. The lead-free piezoelectric materials (PVDF and Lithium Niobate) were assessed with the PZT in order to determine their viability for droplet coalescence. The piezoelectric materials were subjected to mechanical oscillation under resonance in order to allow for optimum performance. The eigen-frequency analysis provided the resonance frequencies of 19.61, 26.04 and 57.80 kHz for PVDF, PZT and Lithium niobate, respectively. Moreover, the acoustic pressure in the emulsion domain varied in magnitude and distribution. The order of the coalescence time for the binary droplets followed the order PZT<Lithium niobate<PVDF.