水溶液中氯化铯与糖(D-葡萄糖、D-果糖和蔗糖)相互作用的热力学参数研究(298.15K)

用钾离子选择性电极为测量电极,氯离子选择性电极为参比电极,设计组成无液接电池,用于氯化铯-糖(葡萄糖、果糖及蔗糖)-水三元体系中组分之间弱相互作用的热力学性质研究.通过测量电池的电动势获得氯化铯在糖水溶液中的活度系数,根据Scatchard理论推测出糖在氯化铯水溶液中的活度系数.通过Mcmillan-Mayer理论将体系的过量热力学函数与溶液中溶质的相互作用参数相关联,获得氯化铯与糖在水溶液中相互作用的吉布斯自由能参数及盐效应常数.运用结构相互作用模型、糖的羟基水化效应及色散能理论,探讨体系中溶质-溶质、溶质-溶剂间的相互作用及糖的立体结构和金属离子体积对热力学参数的影响.

Thermodynamic Parameters of Interaction of CsCl with D-Glucose, D-Fructose and D-Sucrose in Water at 298.15 K

Electrochemical cells with a potassium ion selectivity electrode(Na-ISE) as a measuring electrode versus a chloride ion selectivity electrode as a reference electrode(Cl-ISE) were used to investigate the interaction of solute-solute and solute-solvent in the CsCl-saccharide(D-glucose, D-fructose and sucrose)-water ternary system at 298.15 K. The activity coefficients of CsCl in saccharides aqueous solutions can be determined through the measurements of electromotive force, and the activity coefficients of saccharides in CsCl aqueous solutions can be evaluated in terms of the Scatchard theory. The McMillan-Mayer theory is employed to relate the excess thermodynamic function with a series of interaction parameters of solute in water so as to obtain the pair Gibbs free energy interaction parameters and salting constant. These parameters have been analyzed by using the model of structural interaction, the effect of hydration of hydroxyl of saccharide and the theory of dispersion energy and the stereostructure of saccharides, which indicates that the interactions of these saccharides with CsCl are controlled mostly by the structure and conformation of their molecules in water.