Surfactants in Solution Experimental Observations and Models

2a Self-Assembly into Micelles Representation as Reactions 

The clustering of low molecular weight anionic surfactant molecules to form micelles can also be represented by the following reaction  

Reaction (B) is clearly an extension of Reaction (A), with the former admitting the possibility of counterion binding to the micelle. Additional refinements can be introduced into this reaction. The micelle still carries a net charge of — z, which means that zM+ ions must be present in solution to assure electroneutrality. This may be included in the representation of micellization by writing 

Unless noted otherwise, we use anionic micelles as prototypes that is, we use Reaction (B) to represent the formation of micelles. 

In the case of turbidity t, to a first approximation (Hc/t) is proportional to 1/M (Equation (5.39)). This means that the slope of a plot of r versus c is roughly proportional to M. The break in the curve again corresponds to an increase in the molecular weight of the solute. 

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