Journal of Physical Chemistry, Vol.100, No.38, 15575-15580, 1996
Clustering of Aerosol OT Reversed Micelles as Studied by Nonradiative Energy-Transfer of Solubilized Probes
Water-soluble anionic fluorescent molecules tetrasodium 1,3,6,8-pyrenetetrasulfonate (PyTS) and trisodium 8-hydroxy-1,3,6-pyrenetrisulfonate (pyranine) were solubilized in separate reversed micellar cores in AOT/n-heptane system. The reversed micelle system showed an extent of nonradiative energy transfer from PyTS to pyranine higher than for the aqueous solution system in comparison at a critical probe concentration, [P](c). The values of [P](c), where each micelle is occupied by statistically one probe molecule, were determined as a probe concentration where the solubilized disodium 2,6-naphthalenedisulfonate (NpDS) begins to show the intramicellar excimer fluorescence. The results reveal that at surfactant concentrations higher than 0.1 M the AOT reversed micelles are not randomly dispersed in isolated state in n-heptane but form clusters through intermicellar flocculation.
Keywords:BASE INDICATOR EQUILIBRIA;DYNAMIC LIGHT-SCATTERING;ELECTRON-SPIN-RESONANCE;EXCITED-STATE REACTIONS;IN-OIL MICROEMULSIONS;INVERTED MICELLES;MICRO-EMULSIONS;WATER POOLS;FLUORESCENCE POLARIZATION;W/O MICROEMULSIONS