Dynamics of interacting vesicles and rheology of vesicle suspension in shear flow

Department of Physics of Complex Systems, Weizmann Institute of Science - Rehovot, 76100 Israel

Received: 28 January 2008
Accepted: 15 April 2008

Abstract

We studied the dynamics of isolated vesicles as well as vesicle interactions in semi-dilute vesicle suspensions subjected to a shear flow. We found that the long-range hydrodynamic interactions between vesicles give rise to strong fluctuations of vesicle shape and inclination angle, ϕ, though the functional dependence of ϕ and the transition path to tumbling motion is preserved. The dependence of the suspension viscosity on the viscosity ratio between inner and outer fluids, λ, was found to be non-monotonic and surprisingly growing with λ at the fixed outer fluid viscosity for λ < 1, at odds with recent predictions made for a dilute suspension of non-interacting vesicles.