物理化学学报 >> 2006, Vol. 22 >> Issue (12): 1451-1455.doi: 10.1016/S1872-1508(06)60074-0

研究论文 上一篇    下一篇

正负离子混合表面活性剂双水相界面张力的研究

阮科;张翎;汤皎宁;肖进新   

  1. (北京分子科学国家实验室, 北京大学化学与分子工程学院, 北京 100871; 深圳市特种功能材料重点实验室, 深圳大学, 广东 深圳 518060)
  • 收稿日期:2006-05-05 修回日期:2006-06-28 发布日期:2006-12-06
  • 通讯作者: 肖进新 E-mail:xiaojinxin@pku.edu.cn

Interfacial Tension of the Aqueous Two-phase Systems of Cationic-Anionic Surfactant Mixtures

RUAN Ke;ZHANG Ling;TANG Jiao-Ning;XIAO Jin-Xin   

  1. (Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China; Shenzhen Key Laboratory of Special Functional Materials, Shenzhen University, Shenzhen 518060, P. R. China)
  • Received:2006-05-05 Revised:2006-06-28 Published:2006-12-06
  • Contact: XIAO Jin-Xin E-mail:xiaojinxin@pku.edu.cn

摘要: 用旋转滴法测定了正负离子混合表面活性剂形成的双水相界面张力, 研究了双水相界面张力与表面活性剂的分子结构、正负离子表面活性剂的摩尔比、总浓度、外加无机盐及温度的关系. 结果表明, 双水相界面张力在一定正、负离子表面活性剂的摩尔比时属于超低界面张力范围. 观察到三种界面张力曲线类型, 第一类为摩尔比1:1 的两边的两条曲线, 界面张力随过剩表面活性剂组分的比例增加而降低; 第二类为一条跨过摩尔比1:1的马鞍型曲线; 第三类为位于摩尔比1:1的一边的一条马鞍型曲线. 界面张力曲线的类型主要取决于表面活性剂的分子结构, 包括亲水基类型、疏水链长度及对称性.

关键词: 正负离子表面活性剂, 双水相, 界面张力

Abstract: Interfacial tensions of the aqueous two-phase systems formed by cationic-anionic surfactant mixtures were measured using spinning drop method. The effects of surfactant structure, molar ratio of cationic surfactants to anionic surfactants, surfactant concentration, salt, and temperature on the interfacial tensions were investigated. It was shown that the values of the interfacial tensions of the aqueous two-phase were in the scale of ultra-low interfacial tensions at certain molar ratios of cationic to anionic surfactants. Three types of interfacial tension curves were observed. The first curve comprised two curves that were located on either side of 1:1 molar ratio, and the interfacial tension decreased with the increase of excessed surfactant component. The second one was a saddle-shaped curve that strode over the 1:1 molar ratio. The third type was a saddle-shaped curve that was located beside the 1:1 molar ratio. The types of interfacial tension depended on the molecular structure of the surfactants such as the hydrophilic groups and the lengths and symmetry of hydrophobic chains.

Key words: Cationic-anionic surfactant, Aqueous two-phase system, Interfacial tension