Emulsion rheology and properties of polymerized high internal phase emulsions
High internal phase emulsions are highly concentrated emulsion systems consisting of a large volume of dispersed phase above 0.74. The rheological properties of high internal phase water-in-oil emulsions were measured conducting steady shear, oscillatory shear and creep/recovery experiments. It was found that the yield stress is inversely proportional to the drop size with the exponent of values between 1 and 2. Since the oil phase contains monomeric species, microcellular foams can easily be prepared from high internal phase emulsions. In this study, the microcellular foams combining a couple of thickeners into the conventional formulation of styrene and water system were investigated to understand the effect of viscosity ratio on cell size. Cell size variation on thickener concentration could be explained by a dimensional analysis between the capillary number and the viscosity ratio. Compression properties of foam are important end use properties in many practical applications. Crush strength and Young's modulus of microcellular foams polymerized from high internal phase emulsions were measured and compared from compression tests. Of the foams tested in this study, the foam prepared from the organoclay having reactive group as an oil phase thickener showed outstanding compression properties.
Design and development of a novel high performance emulsion explosive using nanoparticles
Thesis submitted in fulfilment of the requirements for the degree 
Doctor of Technology: Chemical Engineering 
in the Faculty of Engineering 
at the Cape Peninsula University of Technology 
2014
The elastic and viscous properties of emulsions and suspensions
A calculation is made of the elastic properties of a dilute emulsion of one incompressible viscous liquid in another, arising from the interfacial tension between the two phases. A linear relation between the stress tensor, the rate-of-strain tensor and their first time derivatives defines the behaviour at small rates of strain; the three constants involved are expressed as functions of the viscosities of the two components, the drop size (assumed small and uniform), the interfacial tension and the concentration. The relaxation time and retardation time for the system vary directly as the drop diameter and inversely as the interfacial tension. The effect of slip at the interfaces, which might be associated with the presence of a film of a third component introduced as a stabilizer, is also calculated. The values of the rheological constants are appreciably altered if the frictional coefficient specifying the degree of slipping is sufficiently small, but the type of elastic behaviour is unchanged. In the case of a suspension of elastic solid particles in a viscous liquid, slip at the solid-liquid interfaces can cause a change in the type of elastic behaviour.