On the meaning of the spinodal in liquid crystalline solutions

Complete theoretical phase diagrams for the case of a nematic liquid crystal in solution are presented. Several example calculations demonstrate the effects of molecular weight and enthalpic interactions on the expected phase behavior. For two prototypical cases, one corresponding to a low molecular weight compound and the other to its polymeric analog, spinodal curves are calculated based on the necessary and sufficient conditions for phase stability. The phase diagrams for these systems are found to exhibit large metastability gaps.