Eur. Phys. J. E (2006) 21: 11-17
https://doi.org/10.1140/epje/i2006-10039-7

Regular Article

Effective creases and contact angles between membrane domains with high spontaneous curvature

¹ Matière et Systèmes Complexes (MSC), UMR 7057 CNRS and Université Paris 7, 2 place Jussieu, F-75251, Paris Cedex 05, France
² Laboratoire de Physico-Chimie Théorique, UMR 7083 CNRS and ESPCI, 10 rue Vauquelin, F-75231, Paris Cedex 05, France
³ Laboratoire de Physique Statistique, École Normale Supérieure, 24 rue Lhomond, F-75231, Paris Cedex 05, France

^* e-mail: jean-baptiste.fournier@paris7.jussieu.fr

Received: 9 February 2006
Accepted: 8 September 2006
Published online: 28 September 2006

Abstract

We show that the short-scale elastic distortions that are excited in the vicinity of the joint between different lipidic membrane domains (at a scale of ≃ 10nm) may produce a “crease” from the point of view of the standard elastic description of membranes, i.e., an effective discontinuity in the membrane slope at the level of Helfrich's theory. This “discontinuity” may be accounted for by introducing a line tension with an effective angular dependence. We show that domains bearing strong spontaneous curvatures, such as biological rafts, should exhibit creases with a finite contact angle, almost prescribed, corresponding to a steep extremum of the line energy. Finite contact angles might also occur in symmetric membranes from the recruitment of impurities at the boundary.