Promoting ultrasonic cavitation via Negative-Curvature nanoparticles

• Published in: Ultrasonics sonochemistry 2024-07, Vol.107, p.106924, Article 106924
• Main Authors: Wu, Zhouling, Liu, Xiaobin, Guo, Huiying, Huang, Jie, He, Guangyu, Chen, Hongyu, Liu, Xueyang
• Format: Article
• Language: English
• Subjects: Bubble nucleation; Cavitation bubbles; Negative-curvature nanoparticles; Original; Radical-induced color change; Ultrasonication
• ISSN: 1350-4177; 1873-2828; 1873-2828
• DOI: 10.1016/j.ultsonch.2024.106924

It is a challenge to study the nucleation of cavitation bubbles, which critically depends on nanoscale morphological features. Our recent advances in synthesizing colloidal negative-curvature nanoparticles (NGC-NPs) offer a rare opportunity, in comparison to the conventional studies of bulk substrates, where it is difficult to obtain consistent and well-defined surface features. In order to quantitatively assess their effects, we exploit the radical-induced color change of [Fe(SCN)6]3−, which turned out to be a more convenient method than the bending of AgNWs and the fluorescence-based methods. We show that the NGC-NPs outperform positive-curvature nanoparticles (PSC-NPs) and homogeneous nucleation, in terms of promoting cavitation. The NGC-NPs provide a higher percentage of gas–solid interface, and thus reduces the activation barrier during the critical stage of bubble nucleation. This leads a higher probability of cavitation and transforms more energy from ultrasonication to radical formation and shockwaves.