Membrane rigidity induced by grafted polymer brush

Abstract

The contribution of neutral polymer brush to the curvature elasticity of the grafting surface is investigated theoretically. Using self-consistent field theory, we accurately evaluate the dependence of bending modulus on parameters including chain length, Flory–Huggins parameter and grafting density and reveal the importance of solvent. The results show that the brush-induced bending modulus follows a complex dependence on grafting density and Flory–Huggins parameter, while it obeys a simple power law with chain length as N³. The method is further applied to calculate the polymer brush's contribution to the elastic properties of PEG-grafted lipid monolayers.