Interactions of solvents with low molar mass and side chain polymer liquid crystals measured by inverse gas chromatography

Inverse gas chromatographic measurements of infinite dilution Flory-Huggins interaction parameters, chi, as well as "hard-core" interaction parameters, chi*, and energy exchange parameters, X-12, are reported for 17 nonpolar hydrocarbon solvents in various phases of hexyloxy- and octyloxycyanobiphenyl liquid crystals. The values are compared with those from a liquid crystalline siloxane polymer substituted with the cyanobiphenyl mesogen. The results are correlated with the structural features of the LC's, and enthalpic and entropic contributions to the interactions are determined. The results suggest that interactions influenced by the mesogen are dominant, and the polymer backbone plays only a relatively minor part in the solution thermodynamics.