Dissociation of acid-base indicators in microemulsions based on nonionic surfactants

Protolytic equilibria and absorption spectra of twelve indicator dyes in mi croemulsions formed in the systems water-hydrocarbon-alcohol-nonionic surfa ctant were studied in relation to the nature and concentrations of the orga nic microphase and supporting electrolyte. The nature of the hydrocarbon an d alcohol components affects the apparent dissociation constants of the ind icators insignificantly, whereas the effect of the surfactant is more notic eable. The microdrop surface in which, probably, the bound dyes are localiz ed exerts the differentiating effect on their acid dissociation.