Characterization of transient cavitation activity during sonochemical modification of magnesium particles

Ultrasonics Sonochemistry

Nikolai V. Dezhkunov¹  Sviatlana A. Ulasevich²  Nadzeya Brezhneva³  Ekaterina V. Skorb³ 

[1] Belarusian State University, Leningradskaya str. 14, Minsk 220030, Belarus;Belarusian State University of Informatics and Radioelectronics, P. Brovki str. 10, Minsk 220013, Belarus;Infochemistry Scientific Center of ITMO University, Lomonosova str. 9, Saint Petersburg 191002, Russia;

关键词: Sonochemistry;    Transient cavitation;    Cavitation bubbles;    Magnesium nanostructuring;    Magnesium hydroxide;    Hydrogen storage;   

DOI  :  

来源: DOAJ

【 摘 要 】

Investigation of the cavitation activity during ultrasonic treatment of magnesium particles during nanostructuring has been performed. Cavitation activity is recorded in the continuous mode after switching the ultrasound on with the use of ICA-5DM cavitometer. It has been demonstrated that this characteristic of the cavitation zone may be varied in a wide range of constant output parameters of the generator. The speed and nature of the cavitation activity alteration depended on the concentration of Mg particles in the suspension and the properties of the medium in which the sonochemical treatment has been performed. Three stages of the cavitation area evolution can be distinguished: 1 – the initial increase in cavitation activity, 2 – reaching a maximum with a subsequent decrease, and 3 – reaching the plateau (or the repeated cycles with feedback loops of enlargement/reduction of the cavitation activity).The ultrasonically treated magnesium particles have been characterized by scanning electron microscopy, X-ray diffraction analysis and thermal analysis. Depending on the nature of the dispersed medium the particles can be characterized by the presence of magnesium hydroxide (brucite) and magnesium hydride. It is possible to reach the incorporation of magnesium hydride in the magnesium hydroxide/magnesium matrix by varying the conditions of ultrasonic treatment (duration of treatment, amplitude, dispersed medium etc.). The influence of the magnesium reactivity is also confirmed by the measurements of cavitation activity in organic dispersed media (ethanol, ethylene glycol) and their aqueous mixtures.

【 授权许可】

Unknown