Rheology of oil/water emulsions - theoretical description and rheometry

Investigatordoc. RNDr. Petr Štern, CSc.
Duration1993 - 1996

Rheological properties of water/oil emulsions manifesting generally wide spectrum of non-Newtonian behaviour will be investigated from point of view of the mechanism of inner structure effects on the rheological behaviour. Depending on the volume fraction and size of particles of both compositions and the type of emulsifying agents, the behaviour of emulsions may be either Newtonian, pseudoplastic, viscoplastic, thixotropic or viscoelastic. Theoretical models so far used do not represent the above stated possible complex rheological behaviour properly. The aim of the investigation is to theoretically characterise particular emulsions by an appropriate model and to use theoretical results for the quantification of the rheological behaviour of significant food and pharmaceutical products. The theoretical results will contribute to the standardization of rheometrical methods, especially in the case of the determination of yield stress of viscoplastic bodies.