Identification of modes in dynamic scattering from ternary polymer mixtures and interdiffusion

Abstract

It is shown that the two exponential modes in dynamic scattering from ternary polymer mixtures cannot in general be identified with the interdiffusion and cooperative diffusion processes, contrary to recent suggestions in the literature. Conditions under which such an identification is possible are obtained. General expressions for the interdiffusion and cooperative diffusion coefficients associated with a given pair of components A and B in a ternary or in general in a multicomponent polymer mixture are obtained in terms of the partial mobilities μ αβ and partial scattering functions S αβ (q) of the A and B homopolymers