Formulation of Disperse Systems: Science and Technology

This book presents comprehensively the science and technology behind the formulation of disperse systems like emulsions, suspensions, foams and others. Starting with a general introduction, the book covers a broad range of topics like the role of different classes of surfactants, stability of disperse systems, formulation of different dispersions, evaluation of formulations and many more. Many examples are included, too. Written by the experienced author and editor Tharwart Tadros, this book is indispensable for every scientist working in the field.

Table of Contents:
Preface GENERAL INTRODUCTION Suspensions Latexes Emulsions Suspoemulsions Multiple Emulsions Nanosuspensions Nanoemulsions Microemulsions Pigment and Ink Dispersions Foams SURFACTANTS USED IN FORMULATION OF DISPERSIONS General Classification of Surface-Active Agents PHYSICAL CHEMISTRY OF SURFACTANT SOLUTIONS AND THE PROCESS OF MICELLISATION Thermodynamics of Micellisation Enthalpy and Entropy of Micellisation DISPERSANTS AND POLYMERIC SURFACTANTS Solution Properties of Polymeric Surfactants General Classification of Polymeric Surfactants Polyelectrolytes ADSORPTION OF SURFACTANTS AT THE AIR/LIQUID, LIQUID/LIQUID, AND SOLID/LIQUID INTERFACES Introduction Adsorption of Surfactants at the Air/Liquid (A/L) and Liquid/Liquid (L/L) Interfaces The Gibbs Adsorption Isotherm Equation of State Approach The Langmuir, Szyszkowski, and Frumkin Equations Interfacial Tension Measurements Adsorption of Surfactants at the Solid/Liquid (S/L) Interface ADSORPTION OF POLYMERIC SURFACTANTS AT THE SOLID/LIQUID INTERFACE Theories of Polymer Adsorption Experimental Techniques for Studying Polymeric Surfactant Adsorption Determination of Segment Density Distribution p(z) and Adsorbed Layer Thickness Examples of the Adsorption Isotherms of Nonionic Polymeric Surfactants COLLOID STABILITY OF DISPERSE SYSTEMS CONTAINING ELECTRICAL DOUBLE LAYERS Origin of Charge on Surfaces Structure of the Electrical Double Layer Stern-Grahame Model of the Double Layer Distinction between Specific and Nonspecific Adsorbed Ions Electrical Double Layer Repulsion van der Waals Attraction Total Energy of Interaction Flocculation of Suspensions Criteria for Stabilisation of Dispersions with Double Layer Interaction STABILITY OF DISPERSE SYSTEMS CONTAINING ADSORBED NONIONIC SURFACTANTS OR POLYMERS: STERIC STABILISATION Introduction Interaction between Particles Containing Adsorbed Nonionic and Polymeric Surfactant Layers (Steric Stabilisation) Mixing Interaction Gmix Elastic Interaction Gel Total Energy of Interaction Criteria for Effective Steric Stabilisation Flocculation of Sterically Stabilised Dispersions FORMULATION OF SOLID/LIQUID DISPERSIONS (SUSPENSIONS) Introduction Preparation of Suspensions Condensation Methods: Nucleation and Growth Dispersion Methods Bulk Properties of Suspensions FORMULATION OF LIQUID/LIQUID DISPERSIONS (EMULSIONS) Introduction Industrial Applications of Emulsions Physical Chemistry of Emulsion Systems Adsorption of Surfactants at the Liquid/Liquid Interface Selection of Emulsifiers Creaming or Sedimentation of Emulsions Flocculation of Emulsions General Rules for Reducing (Eliminating) Flocculation Ostwald Ripening Emulsion Coalescence Phase Inversion FORMULATION OF SUSPOEMULSIONS (MIXTURES OF SUSPENSIONS AND EMULSIONS) Introduction Suspoemulsions in Paints Suspoemulsions in Agrochemicals FORMULATION OF MULTIPLE EMULSIONS Introduction Preparation of Multiple Emulsions Types of Multiple Emulsions Breakdown Processes of Multiple Emulsions Factors Affecting Stability of Multiple Emulsions, and Criteria for Their Stabilisation General Description of Polymeric Surfactants Interaction between Oil or Water Droplets Containing an Adsorbed Polymeric Surfactant: Steric Stabilisation Examples of Multiple Emulsions Using Polymeric Surfactants Characterisation of Multiple Emulsions Rheological Measurements PREPARATION OF NANOSUSPENSIONS Introduction Nucleation and Growth, and Control of Particle Size Distribution Preparation of Nanosuspensions by Bottom-Up Processes Preparation of Nanosuspensions Using the Bottom-Down Process FORMULATION OF NANOEMULSIONS Introduction Mechanism of Emulsification Methods of Emulsification and the Role of Surfactants Preparation of Nanoemulsions Steric Stabilisation and the Role of the Adsorbed Layer Thickness FORMULATION OF MICROEMULSIONS Introduction Thermodynamic Definition of Microemulsions Mixed-Film and Solubilisation Theories of Microemulsions Thermodynamic Theory of Microemulsion Formation Characterisation of Microemulsions Using Scattering Techniques Characterisation of Microemulsions Using Conductivity NMR Measurements Formulation of Microemulsions FORMULATION OF FOAMS Introduction Foam Preparation Foam Structure Classification of Foam Stability Drainage and Thinning of Foam Films Theories of Foam Stability Foam Inhibitors Physical Properties of Foams Experimental Techniques for Studying Foams FORMULATION OF LATEXES Introduction Emulsion Polymerisation Polymeric Surfactants for Stabilisatoin of Preformed Latex Dispersions Dispersion Polymerisation FORMULATION OF PIGMENT AND INK DISPERSIONS Introduction Powder Wetting Breaking of Aggregates and Agglomerates (Deagglomeration) Classification of Dispersants METHODS OF EVALUATING FORMULATIONS AFTER DILUTION Introduction Assessment of the Structure of the Solid/Liquid Interface Assessment of Sedimentation of Suspensions Assessment of Flocculation and Ostwald Ripening (Crystal Growth) Scattering Techniques Measurement of Rate of Flocculation Measurement of Incipient Flocculation Measurement of Crystal Growth (Ostwald Ripening) Bulk Properties of Suspensions: Equilibrium Sediment Volume (or Height) and Redispersion EVALUATING FORMULATIONS WITHOUT DILUTION: RHEOLOGICAL TECHNIQUES Introduction Steady-State Measurements Constant Stress (Creep) Measurements Dynamic (Oscillatory) Measurements ASSESSMENT AND PREDICTION OF CREAMING, SEDIMENTATION, FLOCCULATIO, AND COALESCENCE OF FORMULATIONS Assessment and Prediction of Creaming and Sedimentation Assessment and Prediction of Flocculation Using Rheological Techniques Assessment and Prediction of Emulsion Coalescence Using Rheological Techniques Index

About the Author :
Tharwat F. Tadros is a consultant for various chemical industries. After finishing his PhD at Alexandria University, he was appointed lecturer in Physical Chemistry (1962-1966) at the same university. Between 1966 and 1969, he spent a sabbatical at the Agricultural University of Wageningen and T.N.O in Delft, the Netherlands. Thereafter he worked at I.C.I. and ZENECA until 1994, where he researched various fields of surfactants, emulsions, suspensions, microemulsions, wetting spreading and adhesion, and rheology. During that period he was also appointed visiting professor at Imperial College London, Bristol University and Reading University. In 1992, he was elected President of the International Association of Colloid and Interface Science. Since leaving ZENECA, Dr. Tadros has worked as a consultant and also given several courses in his specialized field. He is the recipient of two medals from the Royal Society of Chemistry in the UK, and has more than 250 scientific papers to his name.