Steady-state anisotropy measurements using an amphiphilic fluorescence probe, (trimethylamino)diphenylhexatriene (TMA-DPH), and an oil-soluble probe, diphenylhexatriene (DPH), are reported for three-component microemulsions, employing didodecyldimethylammonium bromide (DDAB) as the surfactant, simple alkanes, and water. The anisotropies of TMA-DPH are almost constant when oil is added to the microemulsions but decrease upon addition of water. The results are interpreted in terms of a structural model based on geometric packing constraints of surfactant-coated cylinders and spheres. The anisotropy shows local changes at the surfactant-water-oil interface which in turn can be related to global structure.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry