title: Rotational tracer diffusion in binary colloidal sphere mixtures.
abstract: We demonstrate that tracer/host size asymmetry and electrostatic interactions strongly affect rotational self-diffusion in binary mixtures of charged colloidal tracer and host spheres. Tracer diffusion coefficients, measured with time-resolved phosphorescence anisotropy, are compared with calculations of rotational diffusion including two- and three-particle hydrodynamic interactions. We also show that the inverse dependence of the rotational diffusion coefficient on the suspension viscosity is approached only at large size ratios.
authors.affiliation: Van't Hoff Laboratory, Debye Institute, Utrecht University, 3584 CH Utrecht, The Netherlands.
authors.forename: G H
authors.initials: GH
authors.lastname: Koenderink
authors.forename: H
authors.initials: H
authors.lastname: Zhang
authors.forename: M P
authors.initials: MP
authors.lastname: Lettinga
authors.forename: G
authors.initials: G
authors.lastname: Nägele
authors.forename: A P
authors.initials: AP
authors.lastname: Philipse