Correlations in suspensions confined between viscoelastic surfaces: Noncontact microrheology

Abstract

We study theoretically the velocity cross-correlations of a viscous fluid confined in a slit between two viscoelastic media. We analyze the effect of these correlations on the motions of particles suspended in the fluid. The compliance of the confining boundaries gives rise to a long-ranged pair correlation, decaying only as $1/r$ with the interparticle distance $r$. We show how this long-ranged effect may be used to extract the viscoelastic properties of the confining media without embedding tracer particles in them. We discuss the remarkable robustness of such a potential technique with respect to details of the confinement, and its expected statistical advantages over standard two-point microrheology.

6 pages, numerical error corrected

References in corpus (4)

• Anomalous hydrodynamic interaction in a quasi-two-dimensional suspension
• Hydrodynamic interaction in confined geometries
• Correlated particle dynamics in concentrated quasi-two-dimensional suspensions
• Response of a polymer network to the motion of a rigid sphere