Spinodal decomposition in systems containing surfactant molecules

The spinodal decomposition is studied, by using light scattering, in two critical systems containing surfactant molecules. Time evolution of the characteristic wave vector and the intensity distributions are discussed. The data obtained agree with the findings of recent Molecular Dynamic simulations carried out in analogous systems. A comparison with MD data gives indication that in the two systems studied the phase separation process occurs through the formation of different structural coalescing domains. Whereas in a AOT microemulsion system the separation occurs through the formation of irregular bicontinuous-like domains, in a micellar mixture the separation is dominated by micellar domains which depend by thermal fluctuations.