Orientational order in nanolayers of cast polymer films

The spontaneous ordering of fragments of chain molecules near the surface in polymer films is described in terms of the multichain model, which allows for local intra- and interchain segment orientational interactions, as well as for transversal fluctuation of their orientation as an approximation of strong planar orientation order in the layers. Chain packing in the plane-ordered state is impossible unless the interchain interaction parameter has a critical value. This value decreases with chain bending rigidity. The calculated dependences of the limiting values of the quadrupole orientation order parameter on the length of the Kuhn statistical segment describe reasonably well the experimental data obtained in a study of polymer homologue polysaccharides and sulfonated phenyl-containing polymers. The monolayer thickness in films of some polysaccharides and sulfonated phenyl-containing polymers has been calculated from the fit of the theoretical to the experimental data of the surface birefringence on the number of nanolayers.