Elastic Properties and Line Tension of Self-Assembled Bilayer Membranes

TL;DR

This paper uses self-consistent field theory to analyze the elastic properties and line tension of self-assembled bilayer membranes, exploring how microscopic chain characteristics influence these parameters.

Contribution

It provides a systematic theoretical analysis of bilayer membrane elastic moduli and line tension based on amphiphilic chain properties, extending understanding beyond simple monolayer models.

Findings

Calculated bending and Gaussian moduli for bilayer membranes.

Identified the dependence of elastic parameters on hydrophilic volume fraction.

Assessed the validity range of linear elasticity theory for membranes.

Abstract

The elastic properties of a self-assembled bilayer membrane are studied using the self-consistent field theory, applied to a model system composed of flexible amphiphilic chains dissolved in hydrophilic polymeric solvents. Examining the free energy of bilayer membranes with different geometries allows us to calculate their bending modulus, Gaussian modulus, two fourth-order membrane moduli, and the line tension. The dependence of these parameters on the microscopic characteristics of the amphiphilic chain, characterized by the volume fraction of the hydrophilic component, is systematically studied. The theoretical predictions are compared with the results from a simple monolayer model, which approximates a bilayer membrane by two monolayers. Finally the region of validity of the linear elasticity theory is analyzed by examining the higher-order contributions.