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

Specific retention volumes, activity coefficients at infinite dilution, par tial molar excess free energies, partial molar excess enthalpies and entrop ies, partial molar enthalpies and entropies of solution for m-, p-, o-xylen es and m-, p-, o-ethyltoluenes in 3,4'-dimethyl-4-[(4-chlorobenzyl)oxy] azo benzene (DMCBOA) as solvent were determined. The separation of m-, p-, o-xy lenes 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 crysta l is presented. At cooling, starting from isotropic liquid (129.5 degrees C ) a nematic phase of DMCBOA was identified in the range of 109.6-103.6 degr ees C, but m-, p-, o-xylenes and m-, p-, o-ethyltoluenes were separated at temperature ranges 65-48 degrees C and 90-55 degrees C, respectively. (C) 2 000 Elsevier Science B.V. All rights reserved.