Issue
EPL
Volume 82, Number 4, May 2008
Article Number 48002
Number of page(s) 5
Section Interdisciplinary Physics and Related Areas of Science and Technology
DOI http://dx.doi.org/10.1209/0295-5075/82/48002
Published online 06 May 2008
EPL, 82 (2008) 48002
DOI: 10.1209/0295-5075/82/48002

Nanotubes from gelly vesicles

S. Kremer1, C. Campillo2, B. Pepin-Donat2, A. Viallat3 and F. Brochard-Wyart1

1  Laboratoire PCC Institut Curie, CNRS UMR 168, University Paris 6 - 75231 Paris Cedex 05, France, EU
2  Laboratoire Electronique Molculaire Organique et Hybride, UMR 5819 SPrAM (CEA-CNRS-UJF), DRFMC, CEA-Grenoble - 38054 Grenoble Cedex 9, France, EU
3  Laboratoire Adhèsion et Inflammation, U 600 CNRS-INSERM - Luminy, France, EU

sebastien.kremer@curie.fr
brigitte.pepin-donat@cea.fr
brochard@curie.fr

received 26 December 2007; accepted in final form 25 March 2008; published May 2008
published online 6 May 2008

Abstract
Hydrodynamic extrusions of tethers from giant unilamellar vesicles (GUV) enclosing a poly-N-isopropylacrylamide (polyNIPAM) gel are studied. The collapse of the gel upon heating induces a deswelling of the GUV, showing that the membrane is linked to the polymer network. The gelly vesicle is attached to a micro-rod and submitted to a flow (velocity U). Above a threshold velocity (U > Uc) a tether is extruded and reaches a stationary length L$_{\infty}$ $\simeq \tau_{0}U$ in a characteristic time $\tau_{0}$. The vesicle behaves like an entropic spring with a tether length L$_{\infty}$ proportional to the Stokes friction force. Compared to viscous "sol" vesicles, gelly vesicle are much stiffer: L$_{\infty}$ and $\tau_{0}$ being hundred times smaller. We conclude that the mobility of lipids is reduced, only a small portion of the vesicle area being free to flow into the tube.

PACS
87.16.D- - Membranes, bilayers, and vesicles.
82.70.Gg - Gels and sols.
83.50.Ha - Flow in channels.

© EPLA 2008