Interaction parameters anionic-cationic surfactant

A different way was chosen to predict the behavior of the mixtures anionic polyelectrolyte/cationic surfactant [32, 33]. The formal Flory presentation is maintained but the interaction parameter, is assumed to give a complete representation of all types of interactions (including electrical). In these conditions, X, is a more or less adjustable parameter with values which can be out of the scope of the original Flory s definition. An important point, well developed... 

The interaction of cationic fluorocarbon and hydrocarbon surfactants was studied by Tamori et al. [145]. The mixed cmc of diethanolheptadecafluoro-2-2-undecanolammonium chloride and dodecyltrimethylammonium chloride was determined by electric conductivity measurements. Partition coefficients of alcohols (methanol and C4F7H2OH) and a fluorescent probe (pyrene-3-carboxaldehyde) between micelles and the bulk aqueous phase were determined. The data interpreted by a regular solution theory fitted an interaction parameter /3 = 1, indicating a much smaller repulsive interaction between the two cationic surfactants than that between an anionic fiuorinated surfactant and an anionic hydrocarbon-type surfactant. The weak repulsion between the two cationic surfactants was explained by a large difference in their cmc values. 

There are fundamental reasons why to study the effect of pressure on surfactant molecules in solution. While an increase in hydrostatic pressure is similar to a decrease in temperature, it is often not fully appreciated that through a change in pressure one solely changes the space available to the molecules under investigation, whereas through a change in temperature one varies in fact two parameters the energy of the molecules and the space available to them. Therefore, different surfactant molecules will respond to external pressure differently when the intermolecular interactions are varied. This also applies to the same anionic surfactants with different counter cations. Consequently, with the addition of a pressure parameter, new information can be obtained on the structure and dynamics of the surfactant molecules in aqueous solution. 

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