STRUCTURES OF END-GRAFTED POLYMER LAYERS - A SMALL-ANGLE NEUTRON-SCATTERING STUDY

The structures of grafted poly(dimethylsiloxane) layers at the solid-liquid interface, in the regime of high graft density, have been investigated in various solvents, using small-angle neutron scattering techniques. In a poor solvent, the grafted polymer layer is dense with two well-defined boundaries, leading to interference phenomena. In a good solvent, the chains are stretched and exhibit the same behavior as in semidilute solution. Although the average interfacial density profile is smoother than a step function, the "brush" model is in good agreement with our observations.