Acta Chimica Sinica ›› 2012, Vol. 70 ›› Issue (01): 6-14.DOI: 10.6023/A1105252 Previous Articles     Next Articles

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刘国宇a, 顾大明a, 刘海燕a, 丁伟b, 于涛b, 程杰成c   

  1. a. 哈尔滨工业大学理学院化学系, 哈尔滨 150001;
    b. 东北石油大学化学化工学院, 大庆 163318;
    c. 大庆油田有限责任公司科技发展部, 大庆 163453
  • 投稿日期:2011-05-25 修回日期:2011-08-16 发布日期:2012-02-25
  • 通讯作者: 刘国宇
  • 基金资助:


Molecular Dynamics Simulation of Ionic Liquid-type Gemini Imidazolium Surfactants in Aqueous Solutions

Liu Guoyua, Gu Daminga, Liu Haiyana, Ding Weib, Yu Taob, Cheng Jiechengc   

  1. a. Department of Chemistry, School of Sciences, Harbin Institute of Technology, Harbin 150001;
    b. Chemistry and Chemical Engineering College, Northeast Petroleum University, Daqing 163318;
    c. Development Department of Science and Technology, Daqing Oil Field Corp. Ltd., Daqing 163453
  • Received:2011-05-25 Revised:2011-08-16 Published:2012-02-25
  • Supported by:

    National Key Basic Research Program of China(973)(No.2005CB221300)and Postgraduate Innovative Science Research Program of Heilongjiang Province,China(No.YJSCX2008-044HLJ).

The surface activity and the ability of micellization of ionic liquid-type Gemini imidazolium surfactants in aqueous solution were investigated by the molecular dynamics simulation.The simulation re- sults indicate that the surface tension calculated from pressure tensor is lower and need to be corrected by multiplying the modified coefficient.The critical micelle concentration calculated by molecular dynamics simulation is consistent with experimental values,and can be used to discriminate the capacity of micelliza- tion of ionic liquid-type Gemini imidazolium surfactants.As the temperature rises,the micellization of ionic liquid-type Gemini imidazolium surfactants becomes more difficult with the aggravation of molecular movement.In addition,we found that ionic liquid-type Gemini imidazolium surfactants with different spacer lengths should follow the various mechanism of micellization.At S≤6,the self-assembly ball of single molecule begin to form the larger micelle.As the carbon atoms of the alkyl chains on the imidazole increase, the formation ability of the micelles of[Cn-4-Cnim]is enhanced.But the formation ability of the micelles of [C10-S-C10im] decrease with the longer spacer.However,at S>6,one molecule inserts the crooked spacer into the interspace between the alkyl chains of the other molecule which leads to the formation of the larger micelles.Therefore,the micelle formation ability of[C10-S-C10im]enhances because the repulsion forces decrease and the hydrophobic interactions become stronger with the spacer lengths increasing.

Key words: critical micelle concentration, micellization, molecular dynamics simulation, ionic liquid-type Gemini imidazolium surfactant, spacer