Membrane rigidity induced by grafted polymer brush.

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 N(3). The method is further applied to calculate the polymer brush's contribution to the elastic properties of PEG-grafted lipid monolayers.