Review article

Introduction of the Surface Complexation Model into the Theory of Colloid Stability

Nikola Kallay ; Laboratory of Physical Chemistry, Department of Chemistry, Faculty of Science, University of Zagreb, Marulićev trg 19, P.O. Box 163, 10000 Zagreb, Croatia
Suzana Žalac ; Laboratory of Physical Chemistry, Department of Chemistry, Faculty of Science, University of Zagreb, Marulićev trg 19, P.O. Box 163, 10000 Zagreb, Croatia

Abstract

This article shows that the introduction of the Surface Complexation model into the »family« of theories that comprise the Theory of Colloid Stability makes that theory »absolute«. This means that one characterizes the electrical interfacial layer, e.g. by adsorption measurements, and calculates the equilibrium parameters, such as the equilibrium constants of protonation and deprotonation of amphoteric surface OH groups, equilibrium constants of the association of counterions, capacitances of inner and outer interfacial layers and the total concentration of surface sites. From these equilibrium parameters one evaluates the potential at the onset of the diffuse layer (Φ_d) and calculates the electrostatic interaction energy yielding the rate constant of aggregation and the stability coefficient. It is shown that counterion association plays an important role in the aggregation phenomena by reducing the value of potential Φ_d.

Keywords

particle aggregation; electrical interfacial layer; surface potentials; interfacial equilibrium; counterion association; surface complexation model; theory of colloid stability; stability coefficient

Hrčak ID:

131840

URI

https://hrcak.srce.hr/131840

Publication date:

1.8.2001.

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