Criticality of Lamellar Surfaces by Conformational Degrees of Freedom

(Received 10 November 1994, revised 11 April 1995, accepted 29 May 1995)

Abstract
A new model for lamellar surfaces formed by anisotropic molecules is proposed. The molecules have internal degrees of freedom, associated with their flexible section of lenght N at zero temperature. We obtain a 2D non-standard six-vertex model, which is exactly soluble and exhibits a finite order transition. The order and the character of the transition are determined by the dominant term in the 1/N-expansion of the interaction energy. The dependence of the critical temperatures on N is, instead, determined by the non-leading terms in the same expansion.