Formation of highly stabilized orientational structures and tilted smectic phases in low-molecular-weight and polymeric ionic liquid crystals

Abstract

Thermotropic ionic liquid crystalline polymers were synthesized by radical polymerization, polycondensation and polymer reaction. Their thermal properties and orientational behavior were examined. The ionic interaction led to the formation of smectic phases with enhanced thermal stability. A side-chain liquid crystal polymer (IP-PE) with an ionic polymer backbone exhibited smectic C and smectic F phases. However, the nonionic family of IP-PE revealed only a nematic phase. Furthermore, in ion-complex type of liquid crystalline polymers composed of polyamine and mesogenic carboxylic acids, the tilted smectic phases such as smectic C and smectic F phases were also formed. The formation of the tilted smectic phases is strongly influenced by the balance between terminal alkyl chain length and ionic interactions.