Semester Offering: August
 

Types of colloids and their fundamental properties; general appearance and shape; formation of particles; colloidal stability as a sum of attractive and repulsive forces; surface reactions; measurement methods; agglomeration; rheology; association colloids; foams; surface physics; structural analysis. The colloidal principles are discussed on many examples. With demonstration experiments and exercises.

 

Colloid chemistry is the oldest branch of chemistry predating even alchemy. However, the knowledge base of colloid chemistry began to fade from the chemistry curriculum and has only recently had a resurgence due to the importance of nanoparticles. The importance of the basic science of colloid chemistry will be briefly reviewed. Optical experiments (absorption, fluorescence, time-resolved fluorescence, dynamic light scattering etc.) can now be used to elucidate the surface coverage and electrostatic properties of nanoparticles. Colloids and colloidal principles are widespread in daily life, in nature and technical application. Why is milk white and some tooth pastes transparent? What are colloids and what is their behaviour? Colloids are mixtures of different phases and diverse and complex appearance. What can we expect of such systems, how can we use their properties and how can we use their properties. With lots of examples from the daily life in the area of materials and of food, with key experiments, this lecture concerns the interdisciplinary and very broad topic of the colloids.

 

I. Introduction

1. The Significance of Surfaces

2. Colloidal (nano) Particles

II. Van der Waals Forces between Colloidal Particles

1. Intermolecular Forces

2. Forces between Particles in vacuum

3. Forces between particles in a liquid

III. Surfaces and Interfaces

1. Surface Tension and Interfacial Tension

2. Surfaces at Equilibrium

3. Surface Tension Measurement

IV. Wetting on Surfaces

1. Contact Angles

2. Contact Angle Hysteresis

3. Dynamic Wetting Phenomena

V. Wetting in Porous Media

1. Statics of Liquid Imbibitions

2. Dynamics of Liquid Imbibitions

3. Characterization of Porous Media

VI. Electrical Phenomena at Interfaces

1. Electrical Double Layer

2. Electrokinetic Measurements

3. Interaction of double layers

VII. Colloidal Stability

1. Stability of dispersions

2. Kinetics of Rapid Coagulation

3. Kinetics of Slow Coagulation

 

Evans, D.F. and Wennerstroem, H. (1999). The Colloidal Domain. New York, Wiley-VCH.

D. J. Shaw, Introduction to colloid and surface chemistry, 4th edn. London: Butterworth-Heinemann, 1992

 

Adamson, A.W. and Gast, A. P., Physical chemistry of surfaces, 6th ed., New York : Wiley, 1997.

Hiemenz, P.C. and Rajagopolan, R., Principles of Colloid and Surface Chemistry, 3rd ed., Marcel Dekker (1997)

Israelachvili, J.N., Intermolecular and Surface Forces, 2nd ed., Academic Press 1992

 

The final grade will be computed from the following constituent parts: mid-term exam (30%), final exam (40%), and assignments (30%). Closed-book examination is used for both mid-term and final exam.