Theory of nematic ordering driven by hydrogen bonding between rods and solvent molecules

Abstract

ABSTRACT A mean-field theory is introduced to describe nematic () ordering and phase separations in aqueous low-molecular-weight liquid crystalline molecules (or short rodlike molecules). We consider a physical bonding (or a hydrogen bonding) between the rod and solvent (water) molecules. Our theory predicts that the hydrogen bonds between the unlike molecules stabilise the phase and take place novel phase separations on the temperature-concentration plane. Upon increasing the number of functional groups on the rods, capable of forming the physical bond with the solvent molecule, the stable phase region is broadened on the phase diagram. We also find a miscibility window of the phase and closed-loop coexistence curves with upper and lower critical solution temperatures near the phase.