How are Colloidal Dispersions Destroyed Aggregation Processes

Flocculation involves the aggregation of particles without the destruction of their individuality and differs fundamentally from the processes of sintering and particle growth, to be discussed in the next chapter. Since flocculation is the first step in the destruction of a very wide range of colloids, it is important to understand the underlying mechanisms involved. Major research efforts have and are being made to elucidate the details of this process. 

In many examples of rapid coagulation it is assumed that the interaction free energy dominates the process so that one can ignore the contribution from the entropy term. The flocculation 

On the other hand, if the flocculation is caused by the presence of a secondary minimum, then entropy effects can be of major importance and lead to a variety of observed phenomena. 

In this chapter we shall discuss first the coagulation of electrostatically stabilised aqueous dispersions in which entropy effects 

The study of the coagulation of aqueous dispersions of sparingly soluble or insoluble solids (lyophobic colloids) has been one of the main streams of colloid research for over a century. This arises both from its practical importance and from the fact that it was the first colloidal phenomenon for which empirical rules governing its onset were established. Consequently it was also the first for which attempts were made to develop a theoretical interpretation. 

---