A new liquid crystal of considerable value for the separation of closely related solvents by gas chromatography

Abstract

The synthesis, characterisation and mesomorphic properties of a new chiral liquid crystal, (S)-5-(10-undecenyloxy)-2-[[[4-(2-methylbutoxy)phenyl]imino]methyl]phenol (UMBPIMP) are described. The phase transition temperatures of this mesogenic compound have been investigated by optical polarising microscopy, differential scanning calorimetry and inverse gas chromatography. The thermodynamics of UMBPIMP were investigated in order to understand its selectivity as a stationary phase in gas chromatography. Its liquid crystal selectivity was tested using the isomers n-butyl acetate, tert-butyl acetate and iso-butyl acetate, and the isomers n-butyl alcohol, tert-butyl alcohol and iso-butyl alcohol, as model chromatographic probes. The retention diagrams of the isomers were plotted between 30°C and 110°C using inverse gas chromatography. Using the specific retention volume, , parameters such as the Flory–Huggins polymer–solvent interaction, , and hard-core polymer–solvent interaction, , and exchange parameters such as effective energy, X eff, enthalpy, X 12 and entropy, Q 12, were determined for the solvents chosen.