Microphase-separated multicontinuous phase in low-molecular-mass thermotropic liquid crystals

Abstract

Extensive application of chemical thermodynamics to exotic aggregation formed in thermotropic liquid crystals is briefly described. Through thermodynamic analyses and considerations of experimental results on liquid crystals, the unexpected sharing of common properties by thermo- and lyotropic liquid crystals is demonstrated. In some thermotropic liquid crystals, the terminal alkyl chain attached to the molecular core is highly disordered, as indicated by the magnitude of configurational entropy. The molten chain serves as intramolecular solvent (self-solvent), as evidenced by the close similarity between phase diagrams against chain length and composition in the binary system with n-alkane. These facts lead to the quasi-binary picture of thermotropic liquid crystals. Consideration of the thermodynamic potential expanded in terms of density fluctuation gives a new insight into the multicontinuous phases formed in simple systems consisting of anisotropic, rodlike particles.