J. Phys. I France 2 (1992) 263-272
On the isotropic-nematic transition for polymers in liquid crystalsLeon Balents, Randall D. Kamien, Pierre Le Doussal and Eric Zaslow
Lyman Laboratory of Physics, Harvard University, Cambrige, MA 02138, U.S.A.
(Received 24 June 1991, revised 12 August 1991, accepted 21 November 1991)
A system of dilute polymers dissolved in liquid crystal is studied in the isotropic phase. A mean field theory is proposed which undergoes spontaneous breaking of the rational symmetry and reduces to the theory of polymer nematics. In order to eliminate closed loops of polymers from entering into the theory, the polymers are replicated n times and then n is taken to zero similarly to the procedures of de Gennes and des Cloizeaux. The transition is first order, and the presence of the polymers shifts the critical point down, in agreement with physical expectations. The effect of polymer-polymer interactions is discussed.
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