DOI: 10.1140/epje/i2002-10121-2
Polymers grafted to a fluid and flexible membrane: Extreme sensitivity to the grafting density
A. Nicolas and B. FourcadeUMR 5819, Groupe théorie, Département de Recherche Fondamentale sur la Matière Condensée, CEA-Grenoble, 38054 Grenoble cedex 9, France nicolas@drfmc.ceng.cea.fr
bfourcade@cea.fr
(Received 26 November 2002 and Received in final form 17 March 2003 / Published online: 12 May 2003)
Abstract
Equilibrium phase coexistence between two chemical species implies the
equality of the chemical potentials and of the osmotic pressures. We study this
problem on a deformable membrane when one type of the molecules serves as anchor for
polymeric chains immersed in the surrounding medium (considered as a good solvent). We
derive the general conditions for phase coexistence when both the curvature of the
membrane and the density field of the anchor molecule are free to adjust themselves.
We show that curvature favors phase segregation. Our model predicts that membranes
decorated with polymeric chains exhibit new shape bifurcations without equivalent in
fixed density systems.
82.35.Gh - Polymers on surfaces; adhesion.
87.16.Dg - Membranes, bilayers and vesicles.
68.15.+e - Liquid thin films.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2003
