FLUCTUATION-INDUCED ORIENTATIONAL CORRELATIONS IN POLYMER BLENDS AND DIBLOCK COPOLYMER MELTS

In this paper we study the possibility of fluctuation-induced orientat ional correlations in interacting polymer systems. We show how orienta tional correlations can arise solely from isotropic density fluctuatio ns and the screened monomer potentials in the melt. No direct anisotro pic interactions are introduced. The case of homopolymer and diblock c opolymer blends are considered. For the diblock copolymers the fluctua tion-induced anisotropy has a large effect on the shape of the molecul e, whereas for homopolymers it is small and not important at the criti cal point.