Energy Aspects Of Acoustic Cavitation And Sonochemistry

Energy Aspects of Acoustic Cavitation and Sonochemistry: Fundamentals and Engineering covers topics ranging from fundamental modeling to up-scaled experiments. The book relates acoustic cavitation and its intrinsic energy balance to macroscopic physical and chemical events that are analyzed from an energetic perspective. Outcomes are directly projected into practical applications and technological assessments covering energy consumption, thermal dissipation, and energy efficiency of a diverse set of applications in mixed phase synthesis, environmental remediation and materials chemistry. Special interest is dedicated to the sonochemical production of hydrogen and its energetic dimensions. Due to the sensitive energy balance that governs this process, this is seen as a "green process" for the production of future energy carriers. Provides a concise and detailed description of energy conversion and exchange within the single acoustic cavitation bubble and bubble population, accompanying physical and chemical effects Features a comprehensive approach that is supported by experiments and the modeling of energy concentration within the sonochemical reactor, jointly with energy dissipation and damping phenomenon Gives a clear definition of energy efficiency metrics of industrial sono-processes and their application to the main emergent industrial fields harnessing acoustic cavitation and sonochemistry, notably for the production of hydrogen

This book presents the latest research on fundamental aspects of acoustic bubbles, and in particular on various complementary ways to characterize them. It starts with the dynamics of a single bubble under ultrasound, and then addresses few-bubble systems and the formation and development of bubble structures, before briefly reviewing work on isolated bubbles in standing acoustic waves (bubble traps) and multibubble systems where translation and interaction of bubbles play a major role. Further, it explores the interaction of bubbles with objects, and highlights non-spherical bubble dynamics and the respective collapse geometries. It also discusses the important link between bubble dynamics and energy focusing in the bubble, leading to sonochemistry and sonoluminescence. The second chapter focuses on the emission of light by cavitation bubbles at collapse (sonoluminescence) and on the information that can be gained by sonoluminescence (SL) spectroscopy, e.g. the conditions reached inside the bubbles or the nature of the excited species formed. This chapter also includes a section on the use of SL intensity measurement under pulsed ultrasound as an indirect way to estimate bubble size and size distribution. Lastly, since one very important feature of cavitation systems is their sonochemical activity, the final chapter presents chemical characterizations, the care that should be taken in using them, and the possible visualization of chemical activity. It also explores the links between bubble dynamics, SL spectroscopy and sonochemical activity. This book provides a fundamental basis for other books in the Molecular Science: Ultrasound and Sonochemistry series that are more focused on applied aspects of sonochemistry. A basic knowledge of the characterization of cavitation bubbles is indispensable for the optimization of sonochemical processes, and as such the book is useful for specialists (researchers, engineers, PhD students etc.) working in the wide area of ultrasonic processing.

Sonochemistry is studied primarily by chemists and sonoluminescence mainly by physicists, but a single physical phenomenon - acoustic cavitation - unites the two areas. The physics of cavitation bubble collapse, is relatively well understood by acoustical physicists but remains practically unknown to the chemists. By contrast, the chemistry that gives rise to electromagnetic emissions and the acceleration of chemical reactions is familiar to chemists, but practically unknown to acoustical physicists. It is just this knowledge gap that the present volume addresses. The first section of the book addresses the fundamentals of cavitation, leading to a more extensive discussion of the fundamentals of cavitation bubble dynamics in section two. A section on single bubble sonoluminescence follows. The two following sections address the new scientific discipline of sonochemistry, and the volume concludes with a section giving detailed descriptions of the applications of sonochemistry. The mixture of tutorial lectures and detailed research articles means that the book can serve as an introduction as well as a comprehensive and detailed review of these two interesting and topical subjects.

Sonochemistry and cavitation are rapidly increasing in importance in modern chemistry as a result of many significant achievements made in recent years. In this current and comprehensive text, the author clearly details and illustrates these developments as well as the fundamental concepts. Much attention is given to the fundamental problems, such as the general kinetics of sonochemical reactions: energetic yields; the principles of the cavitation diffusion theory; the place of acoustic energy among other physical methods of action on matter; and the new electrical theory of cavitation phenomena, sonochemical reactions and sonoluminescence initiation (the theory developed by Professor Margulis). Results of low-frequency acoustic fields investigations are also observed. Special attention is given to the influence of acoustic fields on chemical reactions in nonaqueous systems, catalytic processes and the initiation of oscillating reactions. This publication is designed to broaden the application of ultrasound in chemical technology and improve the efficiency of existing production processes. Its comprehensiveness makes it a practical handbook which will prove invaluable to a broad readership amongst chemistry, engineering and physics undergraduates, graduates, researchers, and industrialists working in the fields of sonochemistry, ultrasonic and chemical technology, high energy chemistry, acoustics and biology.

As nanomaterials and their end products occupy the pinnacle position of consumer markets, it becomes vital to analyze their generation processes. One of the green chemistry principles underlines the need for unusual energy sources to generate them. Utilizing the extreme energy from the collapse of cavitation bubbles, generated by either ultrasound or hydrodynamic forces, for the generation of nanomaterials is a merit to consider in this "Green Chemical Processing Era." A wide range of nanomaterials have been developed in the past decade using cavitation or coupling cavitation with other techniques such as microwave, photochemistry, and electrochemistry, resulting in nanomaterials with unique morphologies, reduced size, narrow size distribution, and innumerous advantages. While a few currently available books deal with the fundamental aspects of cavitation and sonochemistry, this book is devoted specifically to the technologically important nanomaterials obtained by cavitation.

Sonochemistry and the Acoustic Bubble provides an introduction to the way ultrasound acts on bubbles in a liquid to cause bubbles to collapse violently, leading to localized 'hot spots' in the liquid with temperatures of 5000° celcius and under pressures of several hundred atmospheres. These extreme conditions produce events such as the emission of light, sonoluminescence, with a lifetime of less than a nanosecond, and free radicals that can initiate a host of varied chemical reactions (sonochemistry) in the liquid, all at room temperature. The physics and chemistry behind the phenomena are simply, but comprehensively presented. In addition, potential industrial and medical applications of acoustic cavitation and its chemical effects are described and reviewed. The book is suitable for graduate students working with ultrasound, and for potential chemists and chemical engineers wanting to understand the basics of how ultrasound acts in a liquid to cause chemical and physical effects. Experimental methods on acoustic cavitation and sonochemistry Helps users understand how to readily begin experiments in the field Provides an understanding of the physics behind the phenomenon Contains examples of (possible) industrial applications in chemical engineering and environmental technologies Presents the possibilities for adopting the action of acoustic cavitation with respect to industrial applications

Power ultrasound has been used for many years in two specific industrial areas: cleaning and plastic welding. Over the last ten years an increasing interest has been shown in its potential for use over a much wider range of chemistry and processing which has been grouped together under the general title of sonochemistry. Most of these uses depend on the generation of acoustic cavitation in liquid media but this text, while underlining the importance of the physics and mathematics of cavitation, mainly concentrates on applications of the technology. After an introduction to the topic and some historical background to the uses of power ultrasound the general principles of acoustic cavitation are explored including some background physics, bubble dynamics and factors which influence cavitation. The remainder of the book incorporates a series of applications of sonochemistry which illustrate the types of physical and chemical effects of ultrasonically induced cavitation which will interest chemists and engineers alike. Amongst the major topics included are chemical synthesis, environmental protection and remediation of water, sewage and soils, polymer synthesis and processing, electrochemistry including both analytical and synthetic aspects and plating. The final chapter reviews the range of ultrasonic equipment available in the laboratory and the progress made towards the scale-up of sonochemistry. The level is introductory to semi-advanced and no topic has been taken to a particularly specialist level since it is intended that this should be of general interest to readers with a scientific background.

This book provides an introduction to the fundamental and applied aspects of sonochemistry, discussing a number of basic concepts in sonochemistry, such as how ultrasonic waves interact with gas bubbles in liquids to generate cavitation, and how the high temperatures generated within cavitation bubbles could be estimated. It explains how redox radicals are produced and how to make use of both the physical and chemical forces generated during cavitation for various applications. Intended for academic researchers, industry professionals as well as undergraduate and graduate students, especially those starting on a new research topic or those new to the field, it provides a clear understanding of the concepts and methodologies involved in ultrasonic and sonochemistry.