The lyotropic smectic phase on the Flory lattice

The Flory lattice approach for rod-like molecules is extended to encompass the position-restricted (smectic-A) phase. The phase equilibria conditions are obtained from equity of relevant chemical potentials, together with min imization conditions of the Gibb potential with respect to the system orien tational (Flory disorder index, y) and positional (translational disorder i ndex, xi. in the smectic phase) order.