物理化学学报 >> 2015, Vol. 31 >> Issue (2): 322-328.doi: 10.3866/PKU.WHXB201412012

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疏水链长对聚氧乙烯失水山梨醇脂肪酸酯界面扩张流变性质的影响

李明1,2, 曹冲1, 熊可洁1, 杜凤沛1   

  1. 1. 中国农业大学理学院应用化学系, 北京 100193;
    2. 黑龙江省农业科学院农药应用研究中心, 哈尔滨 150086
  • 收稿日期:2014-09-16 修回日期:2014-12-01 发布日期:2015-01-26
  • 通讯作者: 杜凤沛 E-mail:dufp@cau.edu.cn
  • 基金资助:

    国家公益性行业(农业)科研专项(201103024)资助

Effect of Hydrophobic Chain Length on the Interfacial Dilational Rheological Properties of Polyoxyethylene Sorbitan Fatty Acid Ester

LI Ming1,2, CAO Chong1, XIONG Ke-Jie1, DU Feng-Pei1   

  1. 1. Department of Applied Chemistry, College of Science, China Agriculture University, Beijing 100193, P. R. China;
    2. Research Center of Pesticide Application, Heilongjiang Academy of Agricultural Sciences, Harbin 150086, P. R. China
  • Received:2014-09-16 Revised:2014-12-01 Published:2015-01-26
  • Contact: DU Feng-Pei E-mail:dufp@cau.edu.cn
  • Supported by:

    The project was supported by the Special Fund for Agroscientific Research in the Public Interest of China (201103024).

摘要:

利用悬挂滴方法研究了系列聚氧乙烯失水山梨醇脂肪酸酯(TweenX)在正癸烷-水界面的扩张流变性质. 实验结果表明, 疏水烷基链长较短的Tween20 分子在界面上吸附量较大, 分子排列更紧密, Tween40 和Tween60具有大致相同的“有效截面积”, 导致饱和吸附时界面张力(γcmc)比较接近. TweenX浓度大于临界胶束浓度(cmc)时, 由于Tween20 分子排列的更加紧密, 模量和弹性大于Tween40 和Tween60. 当TweenX的疏水烷基链长达到一定长度时, TweenX的界面膜性质受疏水链长的影响减弱, Tween40和Tween60的扩张参数相差不大.

关键词: 聚氧乙烯失水山梨醇脂肪酸酯, 疏水链长, 界面, 扩张模量, 相角

Abstract:

The dilational rheological properties of a series of polyoxyethylene sorbitan fatty acid surfactants (TweenX) at the decane/water interface have been investigated using the drop shape analysis method. The experiment results showed that larger quantities of the Tween20 molecules with shorter hydrophobic chain lengths were adsorbed at the interface because they could arrange more closely. Tween40 and Tween60 molecules had similar“actual cross-sectional areas”, which meant that their interfacial tensions were also similar at the critical micelle concentration (γcmc). Furthermore, when the bulk concentration exceeded the critical micelle concentration (cmc), the modulus and elasticity of Tween20 were larger than those of Tween40 and Tween60. When the hydrophobic alkyl chain of TweenX reached a certain length, the interfacial film properties of TweenX affected by the hydrophobic chain length decreased, which led to similar dilational parameters.

Key words: Polyoxyethylene sorbitan fatty acid ester, Hydrophobic chain length, Interface, Dilational modulus, Phase angle

MSC2000: 

  • O647