Dynamic Structure Factor of Microemulsions

The dynamic structure factor $G(\mathbf{k},\omega )$ is studied in a time-dependent Ginzburg-Landau model for microemulsions in thermal equilibrium by field-theoretic perturbation methods. For small viscosities, the structure factor develops a peak at a nonzero frequency $\omega$, for fixed wavelengths of the order of the typical domain size of oil and water regions. This implies that the intermediate scattering function oscillates in time. We give a simple explanation for these temporal oscillations by considering the flow through a tube with a radius-dependent tension.