Characterization of Liquids, Dispersions, Emulsions, and Porous Materials Using Ultrasound

Andrei S. Dukhin, Philip J. Goetz

• Publisher: Elsevier
• Year: 2017
• ISBN:
  9780444639073
• Edition: 3
• Topic: Technology & Engineering
• Subtopic: Chemical & Biochemical Engineering
• Index: Technology & Engineering

Characterization of Liquids, Dispersions, Emulsions and Porous Materials Using Ultrasound, Third Edition, presents a scientific background for novel methods of characterizing homogeneous and heterogeneous liquids (dispersions, emulsions, and gels) as well as porous materials. Homogeneous liquids are characterized in rheological terms, whereas particle-size distribution and zeta potential are parameters of heterogeneous liquids. For porous materials, porosity, pore size, and zeta potential are output characteristics. These methods are based on ultrasound, which opens an opportunity for simplifying the sample preparation by eliminating dilution. This in turn, makes measurements faster, easier, precise, suitable for accurate quality control, PAT, and formulation of complex systems.

This book provides theoretical background of acoustics, rheology, colloid science, electrochemistry, and other relevant scientific fields, describing principles of existing instrumentation and, in particular, commercially available instruments. Finally, the book features an extensive list of existing applications.

• Presents a theoretical multi-disciplinary background of several new ultrasound analytical techniques in one place
• Validates the theoretical basis of several new analytical techniques
• Compares the efficiency and applications of various ultrasound techniques
• Lists many ultrasound applications in colloid chemistry
• Contains an extensive bibliography on this multidisciplinary topic

Chapter 1

Introduction

Abstract

This chapter presents a historical overview of studies related to ultrasound propagation through heterogeneous systems; dispersions, emulsions, porous materials, etc. These studies create a fundamental background of ultrasound-based methods for characterizing such heterogeneous systems in terms of particle size, ζ-potential, and viscoelastic properties. Versatility of ultrasound allows collecting such data within one instrument, which differentiates this technology from other methods in this field. Comparison with other methods is also provided.

Keywords

Acoustics; Aggregative stability; Attenuation; Colloid; Dispersion; Double layer; Electroacoustics; Electrochemistry; Electrophoresis; Electrophoretic mobility; Emulsion; Hydrodynamics; Ionic strength; Light scattering; Longitudinal rheology; Nanoparticle; Nanotechnology; Particle size; Pore size; Porosity; Porous material; Rheology; Soft particle; Sound speed; Ultrasound; Zeta potential

Several keywords define the scope of this book's third edition. All the words are mentioned in the title: ultrasound, liquids, nano- and microparticulates, and porous bodies. The keyword, ultrasound, refers to characterization techniques described in this book, while all the other keywords indicate types of objects (such as dispersions and emulsions) that are studied by methods based on ultrasound. Each word is key to a major scientific discipline. Ultrasound establishes acoustics as the main scientific basis for the measuring techniques presented here. The other keywords define hydrodynamics, rheology, porosimetry, and colloidal and interfacial science as disciples that deal with particulates and porous bodies. There is one more scientific discipline we pay more attention to as compared to the previous edition—aqueous and nonaqueous electrochemistry.

Historically, there has been curiously little real communication between acoustics [1–3] and the scientific disciples mentioned above. There is a large body of literature devoted to ultrasound phenomena in liquids, particulates, and porous bodies, but it has been mostly written from the perspective of scientists in the field of acoustics. There is limited recognition of ultrasound phenomena as of real importance for learning the properties of liquids, particulates, and porous bodies and, in turn, developing applications. Scientists in these other fields have not embraced acoustics as an important tool for characterizing their objects of interest. The lack of serious dialogue between these scientific fields is perhaps best demonstrated by the fact that there are no references to ultrasound or acoustics in the major handbooks on colloid and interface science [4,5], rheology [6,7], hydrodynamics [8–12], and porosimetry [13].

One may ask, “Perhaps this link does not exist because it is not important?” To answer this question, let us consider the potential place of ultrasound-related effects within an overall framework of nonequilibrium phenomena. It will be helpful to first classify nonequilibrium phenomena in two dimensions, as outlined in Table 1.1: the first is determined by whether the relevant disturbances are electrical, mechanical, or electromechanical in nature; and the second is based on whether the time domain of that disturbance can be described as stationary, low frequency, or high frequency. The low- and high-frequency ranges are separated based on the relationship between either the electrical or mechanical wavelength, λ, and some system dimension, L.

Light scattering clearly represents electrical phenomena in colloids at high frequency (the wavelength of light is certainly smaller than the system's dimensions). However, until very recently, there was not any mention in textbooks of mechanical or electromechanical phenomena in the region where λ is shorter than the system's dimensions. This would appear to leave two empty spaces in Table 1.1. Such mechanical wavelengths are produced by sound or, when the frequency exceeds our hearing limit of 20 kHz, ultrasound. Ultrasound wavelengths lie in the range from 10 microns to 1 mm whereas the system's dimensions are usually in the range of centimeters. For this reason, we consider ultrasound-related effects to lie within the high-frequency range. One of the empty spaces in Table 1.1 can be filled by acoustic measurements at ultrasound frequencies that characterize nonequilibrium phenomena of a mechanical nature at high frequency. The second empty space can be filled by electroacoustic measurements that permit characterization of electromechanical phenomena at high frequency. This book will help fill these gaps and demonstrate that acoustics (and electroacoustics) can provide useful knowledge to various scientific disciples. As an aside, we do not consider the use of high-power ultrasound for modifying systems here. We only undertake the use of low-power sound as a noninvasive investigation tool that has unique capabilities.

Table 1.1

Colloidal Phenomena

	Electrical Nature	Electromechanical	Mechanical Nature
Stationary	Condu...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Preface to the Third Edition
• Preface to the Second Edition
• Preface to the First Edition
• Chapter 1. Introduction
• Chapter 2. Fundamentals of Interface and Colloid Science
• Chapter 3. Fundamentals of Acoustics in Homogeneous Liquids: Longitudinal Rheology
• Chapter 4. Acoustic Theory for Particulates
• Chapter 5. Electroacoustic Theory
• Chapter 6. Experimental Verification of the Acoustic and Electroacoustic Theories
• Chapter 7. Acoustic and Electroacoustic Measurement Techniques
• Chapter 8. Applications for Dispersions
• Chapter 9. Applications for Nanodispersions
• Chapter 10. Applications for Emulsions and Other Soft Particles
• Chapter 11. Titrations
• Chapter 12. Applications for Ions and Molecules
• Chapter 13. Applications for Porous Bodies
• Chapter 14. Peculiar Applications of Acoustics and Electroacoustics for Characterizing Complex Liquids
• List of Symbols
• Index