Bending elasticity of a curved amphiphilic film decorated anchored copolymers: a small angle neutron scattering study

TL;DR

This study investigates how decorating microemulsion droplets with polyethylene-oxide chains affects the bending elasticity of their surfactant films, using small angle neutron scattering to analyze size and polydispersity changes.

Contribution

It provides experimental validation for a model predicting bending properties of curved films decorated with non-adsorbing polymer chains, considering finite curvature and chain diffusion.

Findings

Bending rigidity remains constant with decoration.

Optimum curvature radius decreases as decoration increases.

Model predictions align well with experimental data.

Abstract

Microemulsion droplets (oil in water stabilized by a surfactant film) are progressively decorated with increasing amounts of poly ethylene- oxide (PEO) chains anchored in the film by the short aliphatic chain grafted at one end of the PEO chain . The evolution of the bending elasticity of the surfactant film with increasing decoration is deduced from the evolution in size and polydispersity of the droplets as reflected by small angle neutron scattering. The optimum curvature radius decreases while the bending rigidity modulus remains practically constant. The experimental results compare well with the predictions of a model developed for the bending properties of a curved film decorated by non-adsorbing polymer chains, which takes into account, the finite curvature of the film and the free diffusion of the chains on the film.