Polymer Molecules at Interfaces: Studies by Small-Angle Neutron Scattering

The behavior of polymer molecules at interfaces is an essential aspect of a wide variety of physical-chemical phenomena. For example, polymer molecules in the fiber-polymer interface play an important role in determining the mechanical properties of composites, and polymer molecules at the liquid-solid interface are critical in the stabilization of colloidal dispersions. In some cases polymer molecules are physically adsorbed at the interface and in other cases they are chemically bonded to the surface at one or more positions along the chain. To simplify the terminology, however, both cases will be referred to as polymer adsorption. The chains in the second case are said to be grafted to the surface. It is an example of this second case that we are concerned with in this paper, and in particular with polymer grafted to a finely divided substrate dispersed in a liquid.