Phase diagrams of mixtures of flexible polymers and nematic liquid crystals in a field

The Flory-Huggins theory of flexible polymers mixtures [P. J. Flory, Principles of Polymer Chemistry (Cornell University Press, Ithaca, 1953)] and the Lebwohl-Lasher model of nematogens [G. Lasher, Phys. Rev. A 5, 1350 (1972); P. A. Lebwohl and G. Lasher, 6, 426 (1972)] are combined to understand the phase behaviors of mixtures of flexible polymers (coils) and small molecular liquid crystals in an external magnetic field. It is found that, due to the field-induced ordering, the phase boundaries shift upwards and the paranematic spinodal regions are narrowed near the paranematic-nematic transition lines; however, the nematic spinodal regions are enlarged.