DYE SOLUBILIZATION IN W O MICROEMULSIONS

The solubilization of methylene blue in W/O microemulsions containing n-heptane or isooctane, sodium bis (2-ethylhexyl)sulphosuccinate (AOT) in the presence and tile absence of 2-ethylhexanol, was studied. The alcohol transforms the W/O ''made up'' microemulsions into Winsor TI o nes; The dye partition between the aqueous phase and the W/O microemul sion mas determined spectrophotometrically. The shift of tile maximum absorption wavelength indicates a preferential transfer of the dimer d ye from the aqueous to microemulsion phase. The preferential transfer is apparent for the concentrations range of the dye within which the s olubilization of the methylene blue in the reverse micelles is far fro m Lire maximum value.