Transitions between mesophases involving cubic phases in the surfactant-water systems. Epitaxial relations and their consequences in a geometrical framework

Abstract

AbsbacL- In order to approach the fascinating structure of the cubic Inesophases, we study phase transitions involving them and another meso phases with simpler structures. In the rust part, we give some results obtained in the C12E06/water binary system, that exhibits the most frequent case of biconfinuous cubic1nesophase, with space group Ia3d, and two transitions toward the hexagonal and lamellar mesophases. X-ray scattering experirnents and some optical observations in polarized fight are presented for oriented single-domains of the mesophases. In the second part, we propose some topological arguments to explain the transformations involved at these two transitions and propose some possible fluctuations associated with them.