Energy of interaction in colloids and its implications in rheological modeling

This work deals with the problem of deriving theoretical connections between rheology and interparticle forces in colloidal suspensions. The nature of interparticle forces determines the colloidal structure (crystalline order due to long range repulsive forces, flocculation due to attractive forces, etc.) and hence, the flow behavior of suspensions. The aim of this article is to discuss how these interactions enter the modeling of rheometric functions, in particular, the shear viscosity. In this sense, the main interactions commonly appearing in colloids are reviewed, as well as the role they play in phase transition behavior. Then, a series of approaches relating the interaction potential to viscosity is examined. The results of applying these models to experimental data are also discussed. Finally, examples of viscosity modeling for different interaction potentials are given, by using the structural model proposed previously by the authors. The possibility of relating the flow behavior of colloidal suspensions to the interaction between particles offers new perspectives for the study and technical applications of these systems. (C) 2002 Elsevier Science B.V. All rights reserved.