Marangoni transport in lipid nanotubesP. G. Dommersnes1, O. Orwar1, 2, F. Brochard-Wyart1 and J. F. Joanny1
1 Institute Curie, UMR 168 - 26 rue d'Ulm, F-75248, Paris Cedex 05, France
2 Department of Physical Chemistry, and Microtechnology Centre Chalmers University of Technology - SE-412 96 Göteborg, Sweden
received 11 August 2004; accepted in final form 23 February 2005
published online 23 March 2005
We give a simple picture of transient and stationary transport in lipid nanotubes connecting two vesicles, when a difference of membrane tension is imposed at time t=0, either by pressing one vesicle with a micro-fiber, or by adding a surplus of membrane lipid. The net result is a transport of membrane from the tense towards the floppy vesicle. In the early stage, the tube remains cylindrical, and the gradient of surface tension gives rise to two opposite flows of the internal liquid: a Marangoni flow towards the direction of high tension, and a Poiseuille flow (induced by Laplace pressures) in the opposite direction. At longer time, the tube reaches a stationary state, where curvature and Laplace pressure are balanced. Marangoni flows dominate for giant vesicles, where Laplace pressure is negligible.
87.16.Dg - Membranes, bilayers, and vesicles.
47.85.Np - Fluidics.
© EDP Sciences 2005