Thermodynamic studies on infinitely dilute solutions of xylenes and ethyltoluenes on 3,4′-dimethyl-4-[(4-chlorobenzyl)oxy]azobenzene liquid crystal

Abstract

Specific retention volumes, activity coefficients at infinite dilution, partial molar excess free energies, partial molar excess enthalpies and entropies, partial molar enthalpies and entropies of solution for m-, p-, o-xylenes and m-, p-, o-ethyltoluenes in 3,4′-dimethyl-4-[(4-chlorobenzyl)oxy] azobenzene (DMCBOA) as solvent were determined. The separation of m-, p-, o-xylenes and m-, p-, o-ethyltoluenes was studied on a packed column with 2.5% DMCBOA on Chromosorb W HP 100–120 mesh. The synthesis of this liquid crystal is presented. At cooling, starting from isotropic liquid (129.5°C) a nematic phase of DMCBOA was identified in the range of 109.6–103.6°C, but m-, p-, o-xylenes and m-, p-, o-ethyltoluenes were separated at temperature ranges 65–48°C and 90–55°C, respectively.