Structure and Dynamics of Colloidal Suspensions Studied by Means of XPCS

Structure and dynamics of suspensions of charged colloidal spheres in water were studied by means of small-angle X-ray scattering and X-ray photon correlation spectroscopy using synchrotron radiation. Experimentally obtained dependences on the scattering vector q of the structure factor S(q), short-time collective diffusion coefficient D(q) and hydrodynamic function H(q) were in good agreement with theoretical predictions. No effect of screening of the hydrodynamic interactions, suggested in the literature, was found. The conditions are discussed at which the maximum of the hydrodynamic function peak value H(q_m) can be obtained experimentally.