ISBN : 9780198828600
today you have probably eaten some, or rubbed others on your body.
Plants, animals (including you) and microorganisms make them, and many everyday products
(e.g. detergents, cosmetics, foodstuffs) contain them.
Surfactant molecules have one part which is soluble in water and another which is not.
This gives surfactant molecules two valuable properties: 1) they adsorb at surfaces (e.g. of an oil droplet in water), and 2) they stick together (aggregate) in water.
The aggregates (micelles) are able to dissolve materials not soluble in water alone, and adsorbed surfactant layers, at the surfaces of particles or (say) oil droplets in water, stop the particles or drops sticking together.
This is why stable emulsions such as milk do not separate into layers.
This book treats the basic physical chemistry and physics underlying the behaviour of surfactant systems.
In this book, you will first learn about some background material including hydrophobic hydration, interfacial tension and capillarity (Section I).
Discussion of surfactant adsorption at liquid/fluid and solid/liquid interfaces is given in Section II, and includes thermodynamics of adsorption, dynamic and rheological aspects of liquid interfaces and the direct characterisation of surfactant monolayers.
In Section III, a description is given of surfactant aggregation to give micelles, lyotropic liquid crystals, microemulsions and Winsor systems. There follows a discussion of surface forces and the way they confer stability on lyophobic colloids and thin liquid films (Section IV). Various dispersions stabilised by adsorbed surfactant or polymer (including solid in liquid dispersions, emulsions and foams) are considered in Section V.
The wetting of solids and liquids is explored in Section VI.
Like surfactants, small solid particles can adsorb at liquid/fluid interfaces, form monolayers and stabilise emulsions and foams.
Such behaviour is covered in Section VII. It is assumed the reader has a knowledge of undergraduate physical chemistry, particularly chemical thermodynamics, and of simple physics.
Mathematics (elementary algebra and calculus) is kept at a level consistent with the straightforward derivation of many of the equations presented.
SECTION I BACKGROUND
1 What are surfactants?
2 Oil and water do not mix: hydrophobic hydration
3 Capillarity, wetting and surface (interfacial) tension
SECTION II ADSORPTION OF SURFACTANTS
4 Adsorption of surfactants at liquid interfaces: thermodynamics
5 Adsorption of surfactants at liquid/vapour and liquid/liquid interfaces
6 Dynamic aspects of liquid interfaces
7 Adsorption of surfactants at solid/liquid interfaces
8 Direct characterisation of adsorbed surfactant layers
SECTION III: AGGREGATION OF SURFACTANTS IN SOLUTION
9 Aggregation of surfactants in aqueous systems
10 Surfactants in systems with oil and water, including microemulsions
Section IV: SURFACE FORCES AND THIN LIQUID FILMS
11 Surface forces and colloidal behaviour
12 Thin liquid films
SECTION V: DISPERSIONS STABILISED BY SURFACTANTS
13 Dispersions of solids in liquids
14 Emulsions and Foams
15 Rheology of colloids
SECTION VI: WETTING OF SOLIDS AND LIQUIDS
SECTION VII: SYSYEMS WITH PARTICLES AT LIQUID INTERFACES
17 Particles in Monolayers and Thin Liquid Films
18 Emulsions stabilised by solid particles
THEMES AND CONNECTIONS