SPINODAL PHASE-SEPARATION IN COMPLEX FLUIDS

We study the early stages of the phase separation of an amphiphilic sy stem into two fluids, one structured and the other not, in the context of a one-component order-parameter model. A generalization of the Lan ger - Bar-on - Miller approximation permits the calculation of the tim e evolution of the structure function in the mixture. Near the structu red-fluid side of the coexistence, we find that the spinodal is much m ore clearly observable and is closer to the binodal than on the unstru ctured side.