Acoustic cavitation at low gas pressures in PZT-based ultrasonic systems

Ultrasonics Sonochemistry

卷:73

Wu Li¹  Muthupandian Ashokkumar²  Parthasarathi Ghosh³  Leslie Y. Yeo⁴  Rajaram Lakkaraju⁴  Joydip Mondal⁵  Amgad R. Rezk⁵ 

[1] Cryogenic Engineering Centre, IIT Kharagpur, Kharagpur 721302, India;

[2] Department of Mechanical Engineering, IIT Kharagpur, Kharagpur 721302, India;

[3] Micro/Nanophysics Research Laboratory, School of Engineering, RMIT University, Melbourne, VIC 3000, Australia;

[4] School of Chemistry, The University of Melbourne, VIC 3010, Australia;

关键词: Sonochemical activity;    Acoustic cavitation;    Cavitation-free radical generation;    Cavitation bubbles;   

DOI  :  

来源: DOAJ

【 摘 要 】

The generation of cavitation-free radicals through evanescent electric field and bulk-streaming was reported when micro-volumes of a liquid were subjected to 10 MHz surface acoustic waves (SAW) on a piezoelectric substrate [Rezk et al., J. Phys. Chem. Lett. 2020, 11, 4655–4661; Rezk et al., Adv. Sci. 2021, 8, 2001983]. In the current study, we have tested a similar hypothesis with PZT-based ultrasonic units (760 kHz and 2 MHz) with varying dissolved gas concentrations, by sonochemiluminescence measurement and iodide dosimetry, to correlate radical generation with dissolved gas concentrations. The dissolved gas concentration was adjusted by controlling the over-head gas pressure. Our study reveals that there is a strong correlation between sonochemical activity and dissolved gas concentration, with negligible sonochemical activity at near-vacuum conditions. We therefore conclude that radical generation is dominated by acoustic cavitation in conventional PZT-based ultrasonic reactors, regardless of the excitation frequency.

【 授权许可】

Unknown