Volume 82, Number 5, June 2008
Article Number 58005
Number of page(s) 6
Section Interdisciplinary Physics and Related Areas of Science and Technology
Published online 29 May 2008
EPL, 82 (2008) 58005
DOI: 10.1209/0295-5075/82/58005

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

V. Kantsler, E. Segre and V. Steinberg

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

received 28 January 2008; accepted in final form 15 April 2008; published June 2008
published online 29 May 2008

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, $\phi$, though the functional dependence of $\phi$ and the transition path to tumbling motion is preserved. The dependence of the suspension viscosity on the viscosity ratio between inner and outer fluids, $\lambda$, was found to be non-monotonic and surprisingly growing with $\lambda$ at the fixed outer fluid viscosity for $\lambda$ < 1, at odds with recent predictions made for a dilute suspension of non-interacting vesicles.

87.16.D- - Membranes, bilayers, and vesicles.
47.61.-k - Micro- and nano- scale flow phenomena.
47.63.-b - Biological fluid dynamics.

© EPLA 2008