Adsorption of polymer solutions on surfactant monolayers: Global phase diagrams

The phase diagram of insoluble surfactant monolayers at the air/water interface is affected by the addition of polymer in the water subphase. The case of a condensation transition is investigated within the framework of a mean-field theory. The interaction of the polymer with the interface leads to an upward shift of the critical temperature and of the critical concentration (if the monomers are more attracted by the surfactant molecules than by the bare interface). In some situations, the phase diagram can display a triple point.