Acta Chimica Sinica ›› 2007, Vol. 65 ›› Issue (18): 2081-2084. Previous Articles    

Reports

季铵盐三聚表面活性剂在空气-水界面上单分子膜的崩溃压和分子极限面积

杨红伟1, 朱谱新*,1, 冯玉军2, 陈志2, 周栋梁1, 吴大诚1   

  1. (1四川大学纺织研究所 成都 610065)
    (2中国科学院成都有机化学研究所 成都 610041)
  • 投稿日期:2006-07-07 修回日期:2006-12-10 发布日期:2007-09-28
  • 通讯作者: 朱谱新

Collapse Pressure and Limited Molecular Area of Quaternary Ammonium Salt Type Trimeric Surfactant in Monolayer at Air-Water Interface

YANG Hong-Wei1; ZHU Pu-Xin*,1; FENG Yu-Jun2; CHEN Zhi2; ZHOU Dong-Liang1; WU Da-Cheng1   

  1. (1 Textile Institute, Sichuan University, Chengdu 610065)
    (2 Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041)
  • Received:2006-07-07 Revised:2006-12-10 Published:2007-09-28
  • Contact: ZHU Pu-Xin

π-A isotherm of a monolayer at air-water interface for a quaternary ammonium salt type trimeric surfactant (shortly called 12-2-12-2-12) was investigated by the Langmuir balance technology. The surface tension at collapse pressure, γcollapse, and the molecular limited area, Alimit, were determined and compared with the surface tension of the surfactant solution at CMC concentration, γcmc. In addition, the molecular average area Acmc was calculated according to the Gibbs adsorption equation. The following relationships were found: AlimitAcmc and γcollapseγcmc. These results were related to a partial dissolution of this surfactant via the spreading of the monolayer to the water subsurface, which was shown by the decrease of the surface pressure of its monolayer with time. The higher the initial surface pressure, the rapider the attenuation of the surface tension.

Key words: quaternary ammonium salt type trimeric surfactant, monolayer, air-water interface