General - the Smoluchowski model

Some general rules apply to the kinetics of coagulation of colloids, which can also be used in the specific case of emulsions discussed in Chapter 12. 

When the colloid destabilization occurs, the kinetics of collapse is often fast. Let us consider that we have a colloid system containing originally n particles per volume. Once destabilized, the particles aggregate by colliding with each other and thus the concentration of particles drops with time. Typieally this phenomenon is represented by the seeond-order equation, often called Smoluchowski model  

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