気液クロマトグラフィーによる液晶物質の熱力学的研究(第2報)液晶-溶質相互作用

概要

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The interaction of three thermotropic liquid crystal substances (I), cholesteryl myristate, cholesteryl palmitate, or cholesteryl oleate, and various alkanes or alcohols (II) was studied by gas-liquid chromatography at various temperatures, its stationary phase being composed of 10% (w/w) of I on Chromosorb W. The logarithm of specific retention volume of II vs. reciprocal of temperature was found linear within each region of smectic, cholesteric, and isotropic liquid phases of I. From specific retention volume at various temperatures, the standard free energy, enthalpy, and entropy of the solution of II in I, Δ_<soln> G^Θ_2,Δ_<soln> H^Θ_2,and Δ_<soln> S^Θ_2,were calculated. Δ_<soln> G^Θ_2 lowered by ca. 2.5 kJ mol^<-1> as II molecules became longer by one methylene group. The addition of hydroxyl group to II resulted in the lowering of Δ_<soln> G^Θ_2 by ca. 10 kJ mol^<-1>. Higher values of Δ_<soln> H^Θ_2 and Δ_<soln> S^Θ_2 were obtained in liquid crystals than in isotropic liquid phase of I, showing an extensive destruction of liquid crystal structure of I. The difference of Δ_<soln> H^Θ_2 and Δ_<soln> S^Θ_2 between liquid crystal and isotropic liquid phase increased as molecules of II became longer. It was concluded that the greater solubility of longer molecules of II, as shown in lower Δ_<soln> G^Θ_2,was mainly due to the contribution of Δ_<soln> S^Θ_2.
社団法人日本薬学会の論文
1978-12-25