Fundamentals of Acoustic Cavitation in Sonochemistry

Acoustic cavitation is the main mechanism for reaction intensification in sonochemistry . This chapter provides an overview of the dynamics, mechanisms and theories of acoustic cavitation. Through mathematical simulation and experimental observation, single bubble cavitation theory describes the radial growth, oscillation and energy behavior of a single bubble in a low frequency acoustic field. In multibubble cavitation , the bubble dynamics and energy are greatly influenced by neighboring bubbles . Many hypotheses, such as rectified diffusion , bubble coalescence, concerted collapse and bubble cloud theory, and experiment methods, are used to describe multibubble behavior and energy intensity. Factors such as liquid properties, acoustic field parameters and heterogeneous characteristics of reaction system influence acoustic cavitation. Adverse effects from heterogeneous characteristics on acoustic cavitation can be analyzed to improve the efficiency of sonochemical reactors. The introduction of sonication into a chemical system allows intensification of many reactions, however, proper design of acoustic equipment is needed to obtain reliable results.