(408a) The Role of Confinement on the Evolution of Surfactant Mesophases

The role of confinement on the micelle-to-vesicle transition when solution containing CTAB micelles is mixed with one containing HDBS micelles is studied using Small-Angle Neutron Scattering (SANS). System confinement has been achieved by packing polystyrene beads of varying dimensions (3, 0.5 and 0.2 micron diameter) into a scattering cell. The two micellar solutions are allowed to mix in the void regions between these beads, and the scattering patterns from surfactant microstructures that develop in the interstitial regions have been studied. These have been compared to the pattern obtained in ?bulk' systems, that is where there were no beads. Our initial analysis indicates the suppression of vesicle formation in the confined systems, with a size distribution of aggregates that is sensitive to the degree of confinement.