Steric stabilisation and flocculation by polymers

Abstract

The theories of steric stabilisation and the main parameters that control stability are briefly reviewed. This followed by description of the methods that can be applied for studying steric interactions. Of these viscoelastic measurements offer an indirect, but simple method, for studying interparticle interaction. The storage modulus (G′) volume fraction (φ) results could be compared with the force-distance curves obtained from direct measurements. The effect of addition of free polymer to sterically stabilised dispersions, i.e. depletion flocculation, was investigated using rheological measurements. The latter was applied to calculate the energy of separation E between the particles in a flocculated structure. E was compared with the free energy of depletion G that was calculated using Asakura and Oosawa as well as Fleer, Scheutjens and Vincent’s theories. © 1991 The Society of Polymer Science, Japan. All Rights Reserved.