Module Title - Non-ideal Materials
Number of credits - 20
This module provides an in depth study of the world of colloidal systems and their industrial importance. The course will concentrate on three main systems, namely suspensions, emulsions and foams and in particular will concentrate on how the interparticle forces control the structure of the colloidal system. The course will start defining colloidal systems and explain their classification.
The module will describe how surfactant molecules can be used to modify the surface tension and form micelles and their importance in the industry as detergents and lubricants. How capillary forces are important in the process of wetting will be considered in some detail.
The stability of colloidal suspensions will be discussed in the terms of the balance of repulsive and attractive forces and the various microstructures that can be obtained when one force dominates over the other. In particular how these forces can be manipulated by the careful addition of pH, salt or polymers will be presented.
The measurements of zeta potentials as a means of characterising and magnitude of the interparticle forces will be discussed in detail.
The contacts between small particles and their role in adhesion and cohesion will be explored.
The use of sols and gels in the manufacture of glasses, ceramics, coatings and catalysts will be explored in terms of fundamental interactions, particular attention will be paid to silica gelation.
Freeze casting of porous filters, coating gelation and rapid gelation techniques will also be covered. The emerging technologies of gel casting will be covered.
The industrial importance of emulsions especially in the food industry will be presented.
Finally foams will be discussed.
This module will also describe how chemistry and interfacial phenomena create structure in complex fluids, specifically emulsions creams and gels which occur in many consumer products.
The module describes measurement methods which can be used to infer structural properties and determine the process conditions (history of shear, time and temperature) which cause structure to break down. These measurements are based on the rheological behaviour of the fluids and the module introduces the concept of rheology and provides an in depth description of the different types of fluid which exist (Newtonian and non-Newtonian and Viscoelastic).
The different types of equipment used to perform rheological measurements and different measurements methods of rotational viscometry and oscillatory rheology are described.