Monolayers of Diblock Copolymer at the Air-Water Interface: The Attractive Monomer-Surface Case

TL;DR

This study combines experimental measurements and theoretical modeling to analyze the behavior of polystyrene-polyethyleneoxide copolymer monolayers at the air-water interface, revealing adsorption energies and density profiles.

Contribution

It introduces a combined experimental and SCMF theoretical approach to accurately describe copolymer monolayers at the air-water interface, including adsorption energies and density profiles.

Findings

SCMF theory agrees well with experiments across surface densities.

Adsorption energy per PEO monomer is about one $k_B T$.

Density profiles vary from dilute to dense regimes.

Abstract

We have studied both experimentally and theoretically the surface pressure isotherms of copolymers of polystyrene-polyethyleneoxide (PS-PEO) at the air-water interface. The SCMF (single chain mean-field) theory provides a very good agreement with the experiments for the entire range of surface densities and shows that the adsorption energy per PEO monomer at the air-water interface is about one $k_B T$. In addition, the chain density profile has been calculated for a variety of surface densities, from the dilute to the very dense ones. The SCMF approach has been complemented by a mean-field approach in the low density regime, where the PEO chains act as a two-dimensional layer. Both theoretical calculations agree with the experiments in this region.