Molecular Crystals and Liquid Crystals, Vol.470, 101-105, 2007
Thermal properties of ionic liquid crystalline copolymers and their nonionic family
Ionic liquid crystalline copolymers and their nonionic family were synthesized. The thermal and orientational properties of these ionic and nonionic families were examined. Moreover, the effects of the ionic groups for the liquid crystal formation were investigated. The nonionic liquid crystalline copolymer formed only a nematic phase with a schlieren texture. The ionic liquid crystalline copolymers exhibited only a smectic A phase due to ionic interactions between ammonium cations and counter anions. A smectic A layer was composed of ionic and nonionic sublayers, which are formed by the hydrophilic ionic groups and the hydrophobic mesogenic side chains, respectively. The thermal stability of the smectic A phase was enhanced by an ionic aggregation.