Crossover in a Critical Microemulsion System

抄録

Static and dynamic light scattering experiments have been performed to study the critical dynamics of fluctuations in a water-in-oil microemulsion system (DDAB/hexane/water). A transition from local to non-local dynamics was observed at a certain temperature above the critical point, where the diffusion coefficient deduced from the relaxation rate changes the sign of the slope in the plot against q² (q: wave number). This unusual behavior was explained by taking into account a new background term, in addition to the background term of Rouch et al. The experiment data were further found to agree excellently with the full mode-mode coupling theory including two background terms.