Hydrodynamic interactions in quasi-two-dimensional colloidal suspensions

Dynamical correlations between colloidal particles, in a quasi-two-dimensional geometry, are measured by optical microscopy. The system consists of charged polystyrene spheres suspended in water and confined between two parallel plates. The long-range electrostatic interaction is screened and the interparticle direct interaction becomes an effective excluded volume interaction. Thus, the observed long-range correlations, between the motion of pairs of particles, are due to the solvent mediated hydrodynamic interactions. Such correlations are observed as a dependence in the interparticle distance of the diffusion coefficients for the normal modes, collective and relative, for which results are presented here for a range of particle concentrations. © 2010 Elsevier B.V.

Colloids; Hydrodynamics; Quasi-two-dimensional Colloidal particle; Colloidal suspensions; Diffusion Coefficients; Direct interactions; Dynamical correlations; Electrostatic interactions; Excluded-volume interactions; Hydrodynamic interaction; Interparticle distances; Long range correlations; Normal modes; Parallel plates; Particle concentrations; Polystyrene spheres; Quasi-two-dimensional; Quasi-two-dimensional geometries; Colloid chemistry; Fluid dynamics; Hydrodynamics; Optical microscopy; Polystyrenes; Two dimensional; Suspensions (fluids)

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