Interface in Demixing Solutions and Polymer Mixtures
This chapter analyzes the problems connected with the interfacial layer in demixing solutions and immiscible blends. In polymeric systems the experimentally found thickness of the interfacial layer may be rather high due to the chain structure of polymer molecules and consequently it is determined by the specific behavior of polymers as compared with low molecular mass substances. A. Vrij and G. J. Roebersen derived equations for the interfacial tension between two demixing solutions based on the W. Cahn-J. E. Hillard theory of interfacial tension in mixtures of low molecular weight substances. R. H. Thomas and R. E. Prud’homme derived the relation describing the diminishing the particle size in the mixture by addition of block-copolymer supposing that diminishing interfacial tension is proportional to diminishing particle size. Vrij and Roebersen analyzed the concentration profile of an interphase and interfacial free energy for solutions of demixing polymers near the critical temperature of mixing, where the coil deformation is small.