Dynamics of Phase Separation between a Lyotropic Dilute Lamellar Phase and an Isotropic Phase

We have studied the dynamics of the phase separation between a dilute lyotropic lamellar phase (smectic) and an isotropic phase in a quaternary (water, sodium dodecyl sulfate, pentanol, dodecane) system. Observation of the phase separation with small-angle light scattering on an oriented sample allows us to demonstrate the anisotropic growth of the isotropic phase inside the lamellar phase. Measurement of the variation of the largest characteristic distance as a function of time indicates that the kinetics of the phase separation follows a power law with a characteristic exponent ⅓.