Monolayers of diblock copolymer at the air-water interface: the attractive monomer-surface case

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 meanfield) theory provides a very good agreement with the experiments for the entire range of surface densities and is consistent with the experiments if an adsorption energy per PEO monomer at the air-water interface of about one k(B)T is taken. 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.