Abstract
The hexagonal cell parameter a of the system sodium dodecyl lauryl sulfate and water as a function of volume concentration in phase shows the functional behavior expected for micelles of finite length: a∝. The interpretation of x-ray data based on finite micelles leads to an alternative description of the hexagonal phase : spherocylindrical micelles of constant radius with length that may grow along the range of the phase. Results are compared with recent statistical-mechanical calculations for the isotropic I- transition. The absence of diffraction in the direction perpendicular to the hexagonal plane is ascribed to polydispersity of micellar length, which also is a necessary condition for the occurrence of direct I- transitions.
- Received 13 December 1991
DOI:https://doi.org/10.1103/PhysRevA.46.3548
©1992 American Physical Society