Emulsions

Emulsions PDF
Get This Book
Author: Tharwat F. Tadros
Publisher: Walter de Gruyter GmbH & Co KG
ISBN: 3110452243
Size: 67.42 MB
Format: PDF, ePub, Mobi
Category : Technology & Engineering
Languages : en
Pages : 242
View: 5829

Chapter 1 General Introduction Definition of emulsions and the role of the emulsifier. Classification based on the nature of the emulsifier. Classification based on the structure of the system. General instability problems with emulsions : creaming/sedimentation, flocculation, Ostwald ripening, coalescence and phase inversion. Importance of emulsions in various industrial applications. Chapter 2 Thermodynamics of Emulsion Formation and Breakdown Application of the second law of thermodynamics for emulsion formation : Balance of energy and entropy and non-spontaneous formation of emulsions. Breakdown of the emulsion by flocculation and coalescence in the absence of an emulsifier. Role of the emulsifier in preventing flocculation and coalescence by creating an energy barrier resulting from the repulsive energies between the droplets. Chapter 3 Interaction Forces between Emulsion Droplets Van der Waals attraction and its dependence on droplet size, Hamaker constant and separation distance between the droplets. Electrostatic repulsion resulting from the presence of electrical double layers and its dependence on surface (or zeta) potential and electrolyte concentration and valency. Combination of the van der Waals attraction with double layer repulsion and the theory of colloid stability. Steric repulsion resulting from the presence of adsorbed non-ionic surfactants and polymers. Combination of van der Waals attraction with steric repulsion and the theory of steric stabilisation. Chapter 4 Adsorption of Surfactants at the Oil/Water Interface Thermodynamic analysis of surfactant adsorption and the Gibbs adsorption isotherm. Calculation of the amount of surfactant adsorption and area per surfactant molecule at the interface. Experimental techniques for measuring the interfacial tension. Chapter 5 Mechanism of Emulsification and the Role of the Emulsifier Description of the factors responsible for droplet deformation and its break-up. Role of surfactant in preventing coalescence during emulsification. Definition of the Gibbs dilational elasticity and the Marangoni effect in preventing coalescence. Chapter 6 Methods of Emulsification Pipe flow, static mixers and high speed stirrers (rotor-stator mixer). Laminar and turbulent flow. Membrane emulsification. High pressure homogenisers and ultrasonic methods. Chapter 7 Selection of Emulsifiers The hydrophilic-lipophilic-balance (HLB) and its application in surfactant selection. Calculation of HLB numbers and the effect of the nature of the oil phase. The phase inversion temperature (PIT) method for emulsifier selection. The cohesive energy ratio method for emulsifier selection. Chapter 8 Creaming/Sedimentation of Emulsions and its prevention Driving force for creaming/sedimentation: effect of gravity, droplet size and density difference between the oil and continuous phase. Calculation of the rate of creaming/sedimentation in dilute emulsions. Influence of increase of the volume fraction of the disperse phase on the rate of creaming/sedimentation. Reduction of creaming/sedimentation: Balance of the density of the two phases, reduction of droplet size and effect of addition of ''thickeners'. Chapter 9 Flocculation of Emulsions and its Prevention Factors affecting flocculation. Calculation of fast and slow flocculation rate. Definition of stability ratio and its dependence on electrolyte concentration and valency. Definition of the critical coagulation concentration and its dependence on electrolyte valency. Reduction of flocculation by enhancing the repulsive forces. Chapter 10 Ostwald Ripening and its Reduction Factors responsible for Ostwald ripening : difference in solubility between small and large droplets and the Kelvin equation. Calculation of the rate of Ostwald ripening. Reduction of Ostwald ripening by incorporation of a small amount of highly insoluble oil. Reduction of Ostwald ripening by the use of strongly adsorbed polymeric surfactant and enhancement of the Gibbs elasticity. Chapter 11 Emulsion Coalescence and its Prevention Driving force for emulsion coalescence : Thinning and disruption of the liquid film between the droplets. The concept of disjoining pressure for prevention of coalescence. Methods for reduction or elimination of coalescence : Use of mixed surfactant films, use of lamellar liquid crystalline phases and use of polymeric surfactants. Chapter 12 Phase Inversion and its Prevention Distinction between catastrophic and transient phase inversion. Influence of the disperse volume fraction and surfactant HLB number. Explanation of the factors responsible for phase inversion. Chapter 13 Characterisation of Emulsions Measurement of droplet size distribution : Optical microscopy and image analysis. Phase contrast and polarising microscopyDiffraction methods. Confocal laser microscopy. Back scattering methods Chapter 14 Industrial Application of Emulsions 14.1 Application in Pharmacy 14.2 Application in Cosmetics 14.3 Application in Agrochemicals 14.4 Application in Paints 14.5 Application in the Oil Industry


Oil Field Emulsions

Oil field Emulsions PDF
Get This Book
Author: Donald B. Dow
Publisher:
ISBN:
Size: 12.53 MB
Format: PDF, ePub
Category : Petroleum
Languages : en
Pages : 112
View: 1958



Practices And Methods Of Preventing And Treating Crude Oil Emulsions

Practices and Methods of Preventing and Treating Crude oil Emulsions PDF
Get This Book
Author: Gerald Bernard Shea
Publisher:
ISBN:
Size: 24.16 MB
Format: PDF, ePub, Docs
Category : Emulsions
Languages : en
Pages : 106
View: 5494



Water Gas Tar Emulsions

Water gas Tar Emulsions PDF
Get This Book
Author: William Wallace Odell
Publisher:
ISBN:
Size: 61.45 MB
Format: PDF, ePub, Mobi
Category : Coal-tar
Languages : en
Pages : 51
View: 363



A Basic Asphalt Emulsion Manual Understanding And Using Emulsions

A Basic Asphalt Emulsion Manual  Understanding and using emulsions PDF
Get This Book
Author: Asphalt Institute
Publisher:
ISBN:
Size: 69.51 MB
Format: PDF, ePub, Mobi
Category : Asphalt
Languages : en
Pages :
View: 2329



Photography With Emulsions

Photography with Emulsions PDF
Get This Book
Author: Sir William de Wiveleslie Abney
Publisher:
ISBN:
Size: 35.76 MB
Format: PDF, ePub
Category : Photographic emulsions
Languages : en
Pages : 300
View: 7490



Emulsions

Emulsions PDF
Get This Book
Author: Johan Sjöblom
Publisher: Springer Science & Business Media
ISBN: 9401124604
Size: 74.70 MB
Format: PDF
Category : Science
Languages : en
Pages : 302
View: 343

Proceedings of the NATO Advanced Research Workshop, Bergen, Norway, June 24-25, 1991


Emulsions

Emulsions PDF
Get This Book
Author: Alexandru Grumezescu
Publisher: Academic Press
ISBN: 0128043776
Size: 14.21 MB
Format: PDF, ePub, Docs
Category : Technology & Engineering
Languages : en
Pages : 768
View: 6487

Emulsions, the third volume of the Nanotechnology in the Food Industry series, is an invaluable resource for anyone in the food industry who needs the most recent information about scientific advances in nanotechnology on this topic. This volume focuses on basic and advanced knowledge about nanoemulsion, and presents an overview of the production methods, materials (solvents, emulsifiers, and functional ingredients), and current analytical techniques that can be used for the identification and characterization of nanoemulsions. The book also discusses the applications of nanoemulsion with special emphasis on systems suitable for utilization within the food industry. This book is useful to a wide audience of food science research professionals and students who are doing research in this field, as well as others interested in recent nanotechnological progress worldwide. Presents fundamentals of nanoemulsions, methods of preparation (high-energy and low-energy techniques), and applications in the food industry Includes research studies of nanoemulsification technology to improve bioavailability of food ingredients and research analysis Offers benefits and methods of risk assessment to ensure food safety Presents cutting-edge encapsulating systems to improve the quality of functional compounds Provides a variety of methods, such as high-shear stirring, high-pressure homogenizers, self-emulsification, phase transitions and phase-inversion, to further research in this field


Solidification Of Emulsions

Solidification of Emulsions PDF
Get This Book
Author: Javed Iqbal
Publisher:
ISBN:
Size: 43.15 MB
Format: PDF, ePub, Mobi
Category :
Languages : en
Pages : 190
View: 1136

The formation of drops and particles has been studied for several decades in chemical and process industries. The generation of drops from phase change materials and their solidification in a direct contact coolant is rarely been addressed. Here, in this study a new concept of drop formation and their solidification is developed and optimized. Emulsions of high melting fats have been prepared and solidified in the form of smaller drops in a direct contact cooling system. The aim of this study was to solidify or crystallize emulsions in the form of smaller particle rather the solidification in a bulk system, which is difficult for controlled solidification. Palm oil was used as model fat for the preparation, Span 20 as an emulsifier for the stability of emulsions. The emulsions were prepared by a magnetic stirrer and a rotor stator mixer at various energy inputs. The drops were generated by injecting the prepared emulsion in a stagnant coolant and a subsequent solidification. The process has the advantages over the classical emulsion solidification mechanism and has potential for its use as an alternative in a controlled release of active pharmaceutical ingredients and also coating of biodegradable materials for their use in diverse fields.


Emulsions

Emulsions PDF
Get This Book
Author: Paul Becher
Publisher: Amer Chemical Society
ISBN:
Size: 53.99 MB
Format: PDF, ePub, Docs
Category : Science
Languages : en
Pages : 513
View: 5599

A great introduction to the study and fomulation of emulsions, this book discusses background theory, physical properties of emulsions, theories of emulsion stability and instability, emulsifying agents and their chemistry, formulation procedures and techniques, and industrial applications of emulsification and demulsification.