Flory theorem for structurally asymmetric mixtures.

The generalization of the Flory theorem for structurally asymmetric mixtures was derived and tested by direct visualization of conformational transformations of brushlike macromolecules embedded in a melt of linear chains. Swelling of a brush molecule was shown to be controlled not only by the degree of polymerization (DP) of the surrounding linear chains, N(B), but also by the DP of the brush's side chains, N, which determines the structural asymmetry of the mixed species. The boundaries of the swelling region were established by scaling analysis as N(2) < N (B) < N (A)/N, where N (A) is the degree of polymerization of the brush backbone. Experiment and theory demonstrated good agreement.