关键词: 热力学性质, 乙苯, 二甲苯, 液晶, 乙氧基, 气液色谱, 相变, 异构体, 苯胺, 苯甲腈 P

The infinite dilution activity coefficients of C8 aroms. were measured in the nematic and isotropic phases of N-(p-ethoxybenzylidene)-p-aminobenzonitrile over a wide temperature range. The partial molar excess enthalpies and entropies of the solutes were evaluated and the results were explained by the statistical theory of solns. Based on p-xylene being retained in the nematic phase, a reduced variable s was defined as (a?- a)/(a?- a0); a0 is the value of a at the crystal-nematic transition point, and a?is the limiting value at high temps. The relation of s with t (t = T/TN1, where TN1 is the nematic-isotropic transition temperature) is consistent with the principle of corresponding states.

Key words: THERMODYNAMIC PROPERTIES, ETHYLBENZENE, DIMETHYLBENZENE, LIQUID CRYSTAL, ETHOXY GROUP, GAS LIQUID CHROMATOGRAPHY, PHASE TRANSFORMATION, ISOMER, ANILINE, BENZONITRILE P