Eur. Phys. J. E 4, 33-43

Local entropic effects of polymers grafted to soft interfaces

T. Bickel¹, C. Jeppesen² and C.M. Marques¹.

¹  L.D.F.C.-UMR 7506, 3 rue de l'Université, 67084 Strasbourg Cedex, France
²  Materials Research Laboratory, University of California, Santa Barbara, CA 93106, USA

(Received 20 April 2000)

Abstract
In this paper, we study the equilibrium properties of polymer chains end-tethered to a fluid membrane. The loss of conformational entropy of the polymer results in an inhomogeneous pressure field that we calculate for Gaussian chains. We estimate the effects of excluded volume through a relation between pressure and concentration. Under the polymer pressure, a soft surface will deform. We calculate the deformation profile for a fluid membrane and show that close to the grafting point, this profile assumes a cone-like shape, independently of the boundary conditions. Interactions between different polymers are also mediated by the membrane deformation. This pair-additive potential is attractive for chains grafted on the same side of the membrane and repulsive otherwise.

PACS
36.20.-r - Macromolecules and polymer molecules.
87.15.He - Dynamics and conformational changes.
87.16.Dg - Membranes, bilayers, and vesicles..


© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2001