EFFECT OF PERSISTENT FLEXIBILITY ON THE ISOTROPIC, NEMATIC AND COLUMNAR ORDERING IN A SELF-ASSEMBLING SYSTEM

Concentrated solutions of reversibly assembling amphiphilic molecules often exhibit a variety of liquid-crystalline mesophases due to the asymmetry of their aggregates. For strongly elongated rod-like micelles flexibility may significantly influence the relative stability of these phases. This question is addressed for a simple model for a self-assembling system of monodisperse linear rod-like aggregates which are considered to be persistent flexible. Analogously to a recent calculation for a self-assembling system in which the rod-like aggregates are assumed to be perfectly rigid, persistent flexible aggregates may exhibit the same isotropic-nematic-columnar progression of phases. However, increasing the flexibility reduces the concentration range over which the nematic phase is stable. For sufficiently flexible aggregates the nematic phase is abandoned altogether and a direct isotropic-columnar transition occurs.