Bending of Membranes by Anchored Polymers

Abstract

Polymers which are attached to a fluid membrane by a single anchor exhibit a dilute mushroom regime and a semi-dilute brush regime. Scaling arguments and explicit calculations for ideal polymers show that the membrane is bent by the anchored polymer: For smooth bends, an anchored mushroom with linear size R_po induces a spontaneous curvature of order T/κR_po, where T and κ are the temperature and the bending rigidity, respectively; for sharp cone-like bends, it induces a bending angle T/2πκ. A brush with mean anchor separation ξ_an leads to a curvature of order (R_po/ξ_an)^2/ν T/κξ_an.