Dispersion of Powders

Tharwat F. Tadros was appointed lecturer in Physical Chemistry at Alexandria University in 1962 and served in this position until 1966. Between 1966 and 1969, he spent his sabbatical leave at the Agricultural University of Wageningen and T.N.O. in Delft, The Netherlands. Thereafter, he joined I.C.I. and ZENECA until 1994, where he researched various fields of surfactants, emulsions, suspensions, microemulsions, wetting, spreading & 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, Tharwat F. Tadros has worked as a consultant for various industries and has also taught 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.

• Preface GENERAL INTRODUCTIONFundamental Knowledge Required for Successful Dispersions of Powders into LiquidsParticle Dimensions in SuspensionsConcentration Range of SuspensionsOutline of the Book FUNDAMENTALS OF WETTING AND SPREADINGIntroductionThe Concept of the Contact Angle Adhesion TensionWork of Adhesion WaWork of CohesionCalculation of Surface Tension and Contact AngleThe Spreading of Liquids on SurfacesContact Angle Hysteresis THE CRITICAL SURFACE TENSION OF WETTING AND THE ROLE OF SURFACTANTS IN POWDER WETTINGThe Critical Surface Tension of WettingTheoretical Basis of the Critical Surface TensionEffect of Surfactant AdsorptionDynamic Processes of Adsorption and WettingWetting of Powders by Liquids STRUCTURE OF THE SOLID-LIQUID INTERFACE AND ELECTROSTATIC STABILIZATIONStructure of the Solid-Liquid InterfaceStructure of the Electrical Double LayerDistinction between Specific and Nonspecific Adsorbed IonsElectrical Double-Layer Repulsionvan der Waals AttractionTotal Energy of InteractionFlocculation of SuspensionsCriteria for Stabilization of Dispersions with Double-Layer Interaction ELECTROKINETIC PHENOMENA AND ZETA POTENTIALStern-Grahame Model of the Double LayerCalculation of Zeta Potential from Particle MobilityMeasurement of Electrophoretic Mobility and Zeta PotentialElectroacoustic Methods GENERAL CLASSIFICATION OF DISPERSING AGENTS AND ADSORPTION OF SURFACTANTS AT THE SOLID/LIQUID INTERFACEClassification of Dispersing Agents ADSORPTION AND CONFORMATION OF POLYMERIC SURFACTANTS AT THE SOLID-LIQUID INTERFACETheories of Polymer AdsorptionExperimental Techniques for Studying Polymeric AdsorptionMeasurement of the Adsorption IsothermMeasurement of the Fraction of Segments pDetermination of the Segment Density Distribution p(z) and Adsorbed Layer Thickness delta hExamples of the Adsorption Isotherms of Nonionic Polymeric SurfactantsAdsorbed Layer Thickness ResultsKinetics of Polymer Adsorption STABILIZATION AND DESTABILIZATION OF SUSPENSIONS USING POLYMERIC SURFACTANTS AND THE THEORY OF STERIC STABILIZATIONIntroductionInteraction between Particles Containing Adsorbed Polymeric Surfactant Layers (Steric Stabilization)Flocculation of Sterically Stabilized DispersionsBridging Flocculation by Polymers and PolyelectrolytesExamples for Suspension Stabilization Using Polymeric SurfactantsPolymeric Surfactants for Stabilization of Preformed Latex Dispersions PROPERTIES OF CONCENTRATED SUSPENSIONSInterparticle Interactions and Their CombinationDefinition of "Dilute", "Concentrated", and "Solid" SuspensionsStates of Suspension on Standing SEDIMENTATION OF SUSPENSIONS AND PREVENTION OF FORMATION OF DILATANT SEDIMENTSSedimentation Rate of SuspensionsPrevention of Sedimentation and Formation of Dilatant Sediments CHARACTERIZATION OF SUSPENSIONS AND ASSESSMENT OF THEIR STABILITYIntroductionAssessment of the Structure of the Solid/Liquid InterfaceAssessment of Sedimentation of SuspensionsAssessment of Flocculation and Ostwald Ripening (Crystal Growth)Scattering TechniquesMeasurement of Rate of FlocculationMeasurement of Incipient FlocculationMeasurement of Crystal Growth (Ostwald Ripening)Bulk Properties of Suspensions: Equilibrium Sediment Volume (or Height) and Redispersion RHEOLOGICAL TECHNIQUES FOR ASSESSMENT OF STABILITY OF SUSPENSIONSIntroductionSteady-State MeasurementsConstant Stress (Creep) MeasurementsDynamic (Oscillatory) Measurements RHEOLOGY OF CONCENTRATED SUSPENSIONSIntroduction

“Therefore, it is an essential and interdisciplinary guideline, and warmly recommended not only to those working in the field of dispersions/suspensions in pharmaceutical, cosmetic, food, paint, ceramic and agricultural industries but also to students, scientists and practitioners in other scientific fields (chemistry/food science & technology/food processing, production, etc).”  (Advances in Food Science, 1 January 2013)