Viscoelastic properties of concentrated latices. Part 1.—Methods of examination

Abstract

Concentrated polystyrene latices form strongly interacting systems, and under appropriate conditions of particle radii, volume fraction and ionic strength the repulsive forces can be strong enough to give rise to measurable viscoelastic behaviour. In this paper an experimental investigation of the viscoelastic behaviour of concentrated latices is described. The methods used included creep compliance and shear-wave propagation. The former was used to determine the low stress viscosities and the latter to determine the shear modulus. The particle radii were varied from 26 to 98 nm and the volume fraction range was 0.2–0.4.