Figure 3.3: Spectrum of dynamic light scattering in the hydrodynamic regime of a binary solution.

A result analogous to the Stokes–Einstein relation is obtained from mode-coupling theory according to [14]:

where x = qξ, b = 0.55 and R = 1.03; Ω_K denotes the Kawasaki function [10]:

This function becomes significant only extremely close to the critical point. Therefore, within the experimentally accessible range, Ω_K(x) ≈ 1 may be assumed. Equations (3.64) and (3.65) describe the same diffusion process. Accordingly, the correlation length of concentration fluctuations in (3.65) corresponds to the particle radius in (3.64):

Original mathematical notation is preserved in the extracted image assets.