Elastic Properties and Line Tension of Self-Assembled Bilayer Membranes

Abstract

<p>The bending moduli and line tension of bilayer membranes self-assembled from diblock copolymers was calculated using the self-consistent field theory. The limitation of the linear elasticity theory (Helfrich model) was evaluated by calculating fourth- order curvature moduli in high curvature systems. It was found that in highly curved membranes, the fourth-order contributions to the bending energy becomes comparable to the low-order terms. The line tension (γL) of membrane pores was also investigated for mixtures of structurally different diblock copolymers. The line ten- sion was found to depend sensitively on the diblock chain topology. Addition of short hydrophobic copolymers was found to reduce the line tensions to negative values, showing that lipid mixtures may be used as pore stabilizers.</p>