Dynamic light scattering from binary-liquid gels

Dynamic light scattering is observed for an entanglement gel, gellan gum, whose solvent is a critical mixture of isobutyric acid and water. We observe a length scale, $l_x$, below which the sample shows two correlation times and above which only one (diffusive) correlation time is seen. This length scale grows as a power law as T→$T_c$. Several observed features of this system, including critical exponents for dynamic and static light scattering, are inconsistent with available model estimates.