What Determines Emulsion Types

The processes of flocculation and coalescence in the context of emulsion stability will be treated in a bit more detail below. At this point it is useful to point out their role in the determination of the final nature of the emulsion. The process leading to emulsion formation usuahy begins with the production of preliminary large drops, probably of both hquid phases. The continuous phase-to-be will be determined by many factors, to be outlined below. In any case, droplets of that phase must disappear rapidly during the process through flocculation and coalescence. The ultimate dispersed phase, on the other hand, must maintain (or reduce) its droplet size during and after processing. 

The emulsification process is so dynamic and complex that an accurate model and theoretical treatment is almost impossible. With certain limitations its is possible to obtain order-of-magnitude estimates of such steps as droplet formation rate and surfactant transport and adsorption rates. However, the work involved is seldom worth the trouble in practice. Flocculation and coagulation rates during preparation are difficult to analyze because of the dynamics of the process and the turbidity of the flow involved. Collision rate theory 

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Nevertheless, a closer look at the conductivity value indicates the presence of multiple emulsions in B and C, the so-caUed abnormal zones, where there is a conflict between the composition and formulation effects. For instance, in the region a multiple w/OAV emulsion is found. In this case, the composition determines what is the main or outer (OAV) emulsion, whereas the formulation induces the secondary droplet-in-drop (w/O) inner emulsion. A similar situation, but with oAV/O multiple emulsions, is found in the B region. The relative amounts of these two emulsion types depend on the emulsification process, particularly on the way the formulation and composition are varied during the stirring. 

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