物理化学学报 >> 2010, Vol. 26 >> Issue (03): 638-642.doi: 10.3866/PKU.WHXB20100331

胶体及界面化学 上一篇    下一篇

系列烷基芳基磺酸盐在水溶液中胶束化的焓-熵补偿现象

于涛, 李钟, 丁伟, 罗石琼, 栾和鑫, 童维, 曲广淼, 李安军, 程杰成   

  1. 大庆石油学院化学化工学院, 黑龙江 大庆 163318; 大庆油田有限责任公司, 黑龙江 大庆 163453
  • 收稿日期:2009-10-14 修回日期:2009-12-07 发布日期:2010-03-03
  • 通讯作者: 于涛, 丁伟 E-mail:yutao915@126.com; dingwei40@126.com

Enthalpy-Entropy Compensation of Micellization of Alkyl Aryl Sulfonates in Aqueous Solutions

YU Tao, LI Zhong, DING Wei, LUO Shi-Qiong, LUAN Huo-Xin, TONG Wei, QU Guang-Miao, LI An-Jun, CHENG Jie-Cheng   

  1. Chemistry and Chemical Engineening College, Daqing Petroleum Institute, Daqing 163318, Heilongjiang Province, P. R. China; Daqing Oil Field Company Limited , Daqing 163453, Heilongjiang Province, P. R. China
  • Received:2009-10-14 Revised:2009-12-07 Published:2010-03-03
  • Contact: YU Tao, DING Wei E-mail:yutao915@126.com; dingwei40@126.com

摘要:

以表面张力法研究了系列烷基芳基磺酸盐在水溶液中胶束化的热力学性质, 并考察了温度与分子结构对胶束化的影响. 结果表明, 烷基芳基磺酸盐在水溶液中胶束化是一个自发过程, 主要来自熵驱动; 随着温度升高, 先有利于胶束化而后又不利于胶束化, 且熵变对吉布斯自由能变的贡献有下降趋势, 而焓变的贡献有增大趋势; 胶束化存在焓-熵补偿现象, 补偿温度Tc均在(306±2) K, 基本不随烷基芳基磺酸盐的分子结构的改变而变化; 随着芳环上短烷基链或长烷基链碳数的增加, 胶束化能力和胶束的稳定性均提高, 而随着芳环向长烷基链中间位置移动, 胶束化能力和胶束的稳定性均下降.

关键词: 烷基芳基磺酸盐, 胶束化, 热力学, 熵驱动, 焓熵补偿

Abstract:

We used a surface tension method to investigate the thermodynamic properties of micellization in aqueous solution for several alkyl aryl sulfonates that were synthesized in our laboratory. The influence of temperature and molecular structure on the micellization is discussed. Results show that the micellization of alkyl aryl sulfonates in aqueous solutions is spontaneous and entropy-driven. As the temperature rises, the micellization is easy initially but then becomes more difficult. The contribution of entropy change to the change in Gibbs free energy tends to decrease but the contribution of enthalpy change to the change in Gibbs free energy tends to increase. The micellization is enthalpy-entropy compensated. The compensation temperature (Tc) is found to be (306±2) K, which is independent of the molecular structure of the alkyl aryl sulfonates. The formation ability and the stability of the micelles increase when the carbon atoms of the short or long alkyl chains on the aromatic rings increase, but decrease as the aromatic rings shift fromthe edge to the middle of the long carbonic chains.

Key words: Alkyl aryl sulfonate, Micellization, Thermodynamics, Entropy-driven, Enthalpy-entropy compensation

MSC2000: 

  • O645