THE DETERMINATION OF SOME PHYSICAL-PROPERTIES OF REVERSE CTAB MICELLES IN 1-HEXANOL

Aggregation numbers and water pool radii of the L2 region of the cetyltrimethylammonium bromide (CTAB)/1-hexanol/H2O system have been studied by carrying out fluorescence quenching measurements using 4-(1-pyrenyl)butyric acid as a probe and N-cetylpyridinium chloride as a quencher. The water pool radii of these reverse micelles depend mainly on the water content while the aggregation numbers only depend on the surfactant amount. Conductimetric measurements and light scattering measurements at 90-degrees for the system are also given. Both sets of results are related to the layer thickness where surfactant and co-surfactant are located. Ion distribution inside the water pool and the surface potential have been calculated using the non-linearized Poisson Boltzmann equation. The surface charges per square metre of micelles obtained for the L2 region are always smaller than 21 mC m-2.