Journal of Rheology, Vol.45, No.2, 451-466, 2001
Rheology of polyampholyte (gelatin)-stabilized colloidal dispersions: The tertiary electroviscous effect
The shear rheology of gelatin-stabilized acrylic and polystyrene latices is investigated as a function of particle concentration, electrolyte concentration, and pH. Independent measurements of the adsorbed polyampholyte amount and layer structure are used to predict the rheology within the context of hard-sphere mappings. Dynamic light-scattering measurements of the hydrodynamic particle diameter of gelatin-coated colloids yield the best predictions of the zero-shear viscosity and can qualitatively predict the observed tertiary electroviscous effect. Comparisons between dispersions demonstrate the effect of hydrophobic anchoring of the adsorbed gelatin on dispersion rheology. (C) 2001 The Society of Rheology.