叔铵盐-烷烃-醇-水四元体系的热力学函数与结构研究

Studies on Thermodynamic Function and Structure Parameters of Tertiary Amine Salt-Alkane-Water Systems

叔铵类（R3N）萃取剂萃取金属离子需在酸性介质中进行,与无机酸先形成铵盐（属阴离子表面活性剂类）,然后与金属配阴离子进行阴离子交换反应。而将R3N制成无机酸盐,作为表面活性剂以微乳液为模型对其进行热力学函数与结构研究尚未见报道。 本文制备了TOA·HCl、N235·HCl、N235·HNO3与N235·HClO44种叔铵无机酸盐,测定了叔铵盐的界面化学性质。以w/o型微乳液的球形颗粒结构为模型,用稀释法测定了叔铵盐（TOA·HCl,N235·HCl,N235·HNO3,N235·HClO4）-烷烃-醇-水四元均相透明体系的结构参数;并用不同醇时,醇由油相（o）转移至界面层（i）的标准自由能变（?）结果表明其结构“颗粒”半径小于0.5nm,表面活性剂叔铵盐的平均聚集数小于0.05,应属醇的反向胶团。 1 实验 1.1 试剂 三正辛胺（TOA,德国）;N235(R3N,R=C5—C10,大连油脂化学厂)。叔铵盐TOA·HCl分别用干法（D）与湿法（W）制备。向TOA中通入干燥HCl气体至饱和,再加入分析量的TOA中和过量的HCl,制得TOA·HCl（D）.TOA与过量10mol/L盐酸振荡平衡,再加入分析量的TOA中和过量酸制得TOA·HCl（W）,样品均为淡黄色蜡状固体,N235·HCl、N235·HNO3、N235·HClO4均用湿法制备。其它试剂均为A.R.级,未进一步处理,水为二次蒸馏水。

Four tertiary amine salts, TOA·HCl, N235·HCl, N235·HNO3, N235·HClO4 were prepared and their interfacial properties were measured. Thermodynamic function of the systems of tertiary amine salt-alcohol-alkane-water was measured by the dilution method and their structure parameters were calculated by using the model of w/o microemul-sion. The results showed that the 'droplet' radii Re<0.5nm. We suggest that the thermo-dynamic stable tetradic system should belong to a kind of reversed micelles contributed by the hydration of alcohol.