Dilational surface elasticity of spread monolayers of polystyrene microparticles

The dependence of the dilational surface elasticity on the surface pressure of the spread monolayers of polystyrene microparticles is studied at the water-air interface. The surface rheological measurements together with the data from optical methods allow the division of the whole range of surface pressures into three zones characterized by different monolayer structures. The extremely high surface elasticity (∼500 mN m(-1)) at surface pressures close to 30 mN m(-1) is similar to the results for the adsorption layer of the complexes formed between silica particles and surfactant molecules and is probably caused by strong hydrophobic attraction between the particles. At the same time, some other characteristic features of the viscoelasticity of the monolayers of polysterene microparticles differ strongly from the properties of previously studied systems.