Effective Screening of Hydrodynamic Interactions in Charged Colloidal Suspensions

Dirk O. Riese; Gerard H. Wegdam; Willem L. Vos; Rudolf Sprik; Denis Fenistein; Jeroen H. H. Bongaerts; Gerhard Grübel

doi:10.1103/PhysRevLett.85.5460

Effective Screening of Hydrodynamic Interactions in Charged Colloidal Suspensions

Dirk O. Riese, Gerard H. Wegdam, Willem L. Vos, Rudolf Sprik, Denis Fenistein, Jeroen H. H. Bongaerts, and Gerhard Grübel

Phys. Rev. Lett. 85, 5460 – Published 18 December 2000

Abstract

We investigate the hydrodynamic interaction in suspensions of charged colloidal silica spheres. The volume fraction as well as the range of the electrostatic repulsion between the spheres is varied. Using a combination of dynamic x-ray scattering, cross-correlated dynamic light scattering, and small angle x-ray scattering, the hydrodynamic function $H (q)$ is determined experimentally. The effective hydrodynamic interactions are found to be screened, if the range of the direct interaction is relatively long and the static density correlations are strong. This observation of effective hydrodynamic screening is in marked contrast to hard-sphere-like systems.

Received 17 February 2000

DOI:https://doi.org/10.1103/PhysRevLett.85.5460

Authors & Affiliations

Dirk O. Riese¹, Gerard H. Wegdam¹, Willem L. Vos¹, Rudolf Sprik¹, Denis Fenistein¹, Jeroen H. H. Bongaerts¹, and Gerhard Grübel²

¹Van der Waals-Zeeman Instituut, Universiteit van Amsterdam, Valckenierstraat 65-67, 1018 XE Amsterdam, The Netherlands
²European Synchrotron Radiation Facility, BP 220, 38043 Grenoble, France