Local structure and density profile of polymer brushes

Brushes of grafted polystyrene have been studied using the classical small-angle neutron scattering techniques. The results show unambigously that the interface, in good solvent, has essentially a parabolic shape, with a small exponential tail. Furthermore, the local structure is similar to that of a semidulute polymer solution with a typical blob size equal to the distance between grafting sites. Mean-field and scaling theories therefore account for these results, within their own range of validity.