Effective creases and contact angles between membrane domains with high spontaneous curvature
Résumé
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 ~10 nm) 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.
