Structure and conformational transitions in grafted polymer chain layers. A new theory

Abstract

A theory that has been developed as an average field approximation describes the structure and conformations of chains consisting of long semirigid polymer chains grafted to an impermeable plane surface. The chains are immersed in a solvent and under the dense grafting conditions there is a marked degree of overlapping of individual chains. Analytical expressions have been derived to describe the density profile for units in the layer, the distribution of chain ends along the layer height and the distribution of local elongation in particular chains. The conformational transition due to collapse of the layer when the temperature falls (deterioration of the solvent quality) has been investigated. In contradistinction to a coil-globule transition occurring in an isolated macromolecule the transition studied is not a true thermodynamic phase transition.