Applied Colloid and Surface Chemistry

Professor Richard M. Pashley and Dr Marilyn E. Karaman, Australian National University, Canberra.

Preface. 1 Introduction. Introduction to the nature of colloidal solutions. The forces involved in colloidal stability. Types of colloidal systems. The link between colloids and surfaces. Wetting properties and their industrial importance. Recommended resource books. Appendices. 2 Surface Tension and Wetting. The equivalence of the force and energy description of surface tension and surface energy. Derivation of the Laplace pressure equation. Methods for determining the surface tension of liquids. Capillary rise and the free energy analysis. The Kelvin equation. The surface energy and cohesion of solids. The contact angle. Industrial Report: Photographic--quality printing. Sample problems. Experiment 2.1: Rod in free surface (RIFS) method for the measurement of the surface tension of liquids. Experiment 2.2: Contact angle measurements. 3 Thermodynamics of Adsorption. Basic surface thermodynamics. Derivation of the Gibbs adsorption isotherm. Determination of surfactant adsorption densities. Industrial Report: Soil microstructure, permeability and interparticle forces. Sample problems. Experiment 3.1: Adsorption of acetic acid on to activated charcoal. 4 Surfactants and Self--assembly. Introduction to surfactants. Common properties of surfactant solutions. Thermodynamics of surfactant self--assembly. Self--assembled surfactant structures. Surfactants and detergency. Industrial Report: Colloid science in detergency. Sample problems. Experiment 4.1: Determination of micelle ionization. 5 Emulsions and Microemulsions. The conditions required to form emulsions and microemulsions. Emulsion polymerization and the production of latex paints. Photographic emulsions. Emulsions in food science. Industrial Report: Colloid science in foods. Experiment 5.1: Determination of the phase behaviour of microemulsions. Experiment 5.2: Determination of the phase behaviour of concentrated surfactant solutions. 6 Charged Colloids. The formation of charged colloids in water. The theory of the diffuse electrical double--layer. The Debye length. The surface charge density. The zeta potential. The Huckel equation. The Smoluchowski equation. Corrections to the Smoluchowski equation. The zeta potential and flocculation. The interaction between double--layers. The Derjaguin approximation. Industrial Report: The use of emulsions in coatings. Sample problems. Experiment 6.1: Zeta potential measurements at the silica/water interface. 7 Van der Waals forces and Colloid Stability. Historical development of van der Waals forces and the Lennard--Jones potential. Dispersion forces. Retarded forces. Van der Waals forces between macroscopic bodies. Theory of the Hamaker constant. Use of Hamaker constants. The DLVO theory of colloid stability. Flocculation. Some notes on van der Waals forces. Industrial Report: Surface chemistry in water treatment. Sample problems. 8 Bubble Coalescence, Foams and Thin Surfactant Films. Thin--liquid--film stability and the effects of surfactants. Thin--film elasticity. Repulsive forces in thin liquid films. Froth flotation. The Langmuir trough. Langmuir--Blodgett films. Experiment 8.1: Flotation of powdered silica. Appendices. 1 Useful Information. 2 Mathematical Notes on the Poisson--Boltzmann Equation. 3 Notes on Three--dimensional Differential Calculus and the Fundamental Equations of Electrostatics.