Formulation of Disperse Systems

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.

• Preface GENERAL INTRODUCTIONSuspensionsLatexesEmulsionsSuspoemulsionsMultiple EmulsionsNanosuspensionsNanoemulsionsMicroemulsionsPigment and Ink DispersionsFoams SURFACTANTS USED IN FORMULATION OF DISPERSIONSGeneral Classification of Surface-Active Agents PHYSICAL CHEMISTRY OF SURFACTANT SOLUTIONS AND THE PROCESS OF MICELLISATIONThermodynamics of MicellisationEnthalpy and Entropy of Micellisation DISPERSANTS AND POLYMERIC SURFACTANTSSolution Properties of Polymeric SurfactantsGeneral Classification of Polymeric SurfactantsPolyelectrolytes ADSORPTION OF SURFACTANTS AT THE AIR/LIQUID, LIQUID/LIQUID, AND SOLID/LIQUID INTERFACESIntroductionAdsorption of Surfactants at the Air/Liquid (A/L) and Liquid/Liquid (L/L) InterfacesThe Gibbs Adsorption IsothermEquation of State ApproachThe Langmuir, Szyszkowski, and Frumkin EquationsInterfacial Tension MeasurementsAdsorption of Surfactants at the Solid/Liquid (S/L) Interface ADSORPTION OF POLYMERIC SURFACTANTS AT THE SOLID/LIQUID INTERFACETheories of Polymer AdsorptionExperimental Techniques for Studying Polymeric Surfactant AdsorptionDetermination of Segment Density Distribution p(z) and Adsorbed Layer ThicknessExamples of the Adsorption Isotherms of Nonionic Polymeric Surfactants COLLOID STABILITY OF DISPERSE SYSTEMS CONTAINING ELECTRICAL DOUBLE LAYERSOrigin of Charge on SurfacesStructure of the Electrical Double LayerStern-Grahame Model of the Double LayerDistinction between Specific and Nonspecific Adsorbed IonsElectrical Double Layer Repulsionvan der Waals AttractionTotal Energy of InteractionFlocculation of SuspensionsCriteria for Stabilisation of Dispersions with Double Layer Interaction STABILITY OF DISPERSE SYSTEMS CONTAINING ADSORBED NONIONIC SURFACTANTS OR POLYMERS: STERIC STABILISATIONIntroductionInteraction between Particles Containing Adsorbed Nonionic and Polymeric Surfactant Layers (Steric Stabilisation)Mixing Interaction GmixElastic Interaction GelTotal Energy of InteractionCriteria for Effective Steric StabilisationFlocculation of Sterically Stabilised Dispersions FORMULATION OF SOLID/LIQUID DISPERSIONS (SUSPENSIONS)IntroductionPreparation of SuspensionsCondensation Methods: Nucleation and GrowthDispersion MethodsBulk Properties of Suspensions FORMULATION OF LIQUID/LIQUID DISPERSIONS (EMULSIONS)IntroductionIndustrial Applications of EmulsionsPhysical Chemistry of Emulsion SystemsAdsorption of Surfactants at the Liquid/Liquid InterfaceSelection of EmulsifiersCreaming or Sedimentation of EmulsionsFlocculation of EmulsionsGeneral Rules for Reducing (Eliminating) FlocculationOstwald RipeningEmulsion CoalescencePhase Inversion FORMULATION OF SUSPOEMULSIONS (MIXTURES OF SUSPENSIONS AND EMULSIONS)IntroductionSuspoemulsions in PaintsSuspoemulsions in Agrochemicals FORMULATION OF MULTIPLE EMULSIONSIntroductionPreparation of Multiple EmulsionsTypes of Multiple EmulsionsBreakdown Processes of Multiple EmulsionsFactors Affecting Stability of Multiple Emulsions, and Criteria for Their StabilisationGeneral Description of Polymeric SurfactantsInteraction between Oil or Water Droplets Containing an Adsorbed Polymeric Surfactant: Steric StabilisationExamples of Multiple Emulsions Using Polymeric SurfactantsCharacterisation of Multiple EmulsionsRheological Measurements PREPARATION OF NANOSUSPENSIONSIntroductionNucleation and Growth, and Control of Particle Size DistributionPreparation of Nanosuspensions by Bottom-Up ProcessesPreparation of Nanosuspensions Using the Bottom-Down Process FORMULATION OF NANOEMULSIONSIntroductionMechanism of EmulsificationMethods of Emulsification and the Role of SurfactantsPreparation of NanoemulsionsSteric Stabilisation and the Role of the Adsorbed Layer Thickness FORMULATION OF MICROEMULSIONSIntroductionThermodynamic Definition of MicroemulsionsMixed-Film and Solubilisation Theories of MicroemulsionsThermodynamic Theory of Microemulsion FormationCharacterisation of Microemulsions Using Scattering TechniquesCharacterisation of Microemulsions Using ConductivityNMR MeasurementsFormulation of Microemulsions FORMULATION OF FOAMSIntroductionFoam PreparationFoam StructureClassification of Foam StabilityDrainage and Thinning of Foam FilmsTheories of Foam StabilityFoam InhibitorsPhysical Properties of FoamsExperimental Techniques for Studying Foams FORMULATION OF LATEXESIntroductionEmulsion PolymerisationPolymeric Surfactants for Stabilisatoin of Preformed Latex DispersionsDispersion Polymerisation FORMULATION OF PIGMENT AND INK DISPERSIONSIntroductionPowder WettingBreaking of Aggregates and Agglomerates (Deagglomeration)Classification of Dispersants METHODS OF EVALUATING FORMULATIONS AFTER DILUTIONIntroductionAssessment 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 EVALUATING FORMULATIONS WITHOUT DILUTION: RHEOLOGICAL TECHNIQUESIntroductionSteady-State MeasurementsConstant Stress (Creep) MeasurementsDynamic (Oscillatory) Measurements ASSESSMENT AND PREDICTION OF CREAMING, SEDIMENTATION, FLOCCULATIO, AND COALESCENCE OF FORMULATIONSAssessment and Prediction of Creaming and SedimentationAssessment and Prediction of Flocculation Using Rheological TechniquesAssessment and Prediction of Emulsion Coalescence Using Rheological Techniques Index