物理化学学报 >> 2016, Vol. 32 >> Issue (5): 1168-1174.doi: 10.3866/PKU.WHXB201602186

研究论文 上一篇    下一篇

分子动力学模拟电解质对阴非离子表面活性剂界面行为的影响

刘子瑜1,*(),廖琦2,靳志强1,张磊1,张路1,*()   

  1. 1 中国科学院理化技术研究所,北京100190
    2 中国科学院化学研究所,北京100190
  • 收稿日期:2016-01-12 发布日期:2016-05-07
  • 通讯作者: 刘子瑜,张路 E-mail:ziyukelly@126.com;luyiqiao@hotmail.com

Effect of Electrolytes on the Interfacial Behavior of Nonionic-Anionic Surfactant Solutions Using Molecular Dynamics Simulations

Zi-Yu LIU1,*(),Qi LIAO2,Zhi-Qiang JIN1,Lei ZHANG1,Lu ZHANG1,*()   

  1. 1 Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
    2 Technical Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
  • Received:2016-01-12 Published:2016-05-07
  • Contact: Zi-Yu LIU,Lu ZHANG E-mail:ziyukelly@126.com;luyiqiao@hotmail.com

摘要:

通过分子动力学(MD)方法研究了不同类型电解质对阴非离子表面活性剂C12EO3C油水界面性能的影响。运用z轴质量密度分布、径向分布函数、分子间相互作用配位数、空间分布函数及均方根位移五种模拟参数来分析电解质与阴非离子表面活性剂的相互作用情况。研究表明,三种离子的加入均对水分子与表面活性剂亲水基形成的水化层结构产生影响,且从微观层面验证三种离子对表面活性剂亲水基相互作用强度大小顺序为Na+ < Ca2+ < Mg2+。通过扩散模拟结果可以较好地解释离子加入对界面张力平衡时间的影响情况。这对指导实验方向、制订最佳复配方案具有重要意义。

关键词: 分子动力学模拟, 电解质, 阴非离子表面活性剂, 水化层, 相互作用

Abstract:

The effect of electrolytes on the interfacial behavior of nonionic-anionic surfactant solutions is studied using molecular dynamics (MD) simulations. The z-dependent surfactant density, radial distribution, coordination number, spatial distribution function, and mean-squared displacement are used to analyze the interaction of electrolytes and surfactants. Based on our simulated results, the three counter ions Na+, Ca2+, and Mg2+ have an effect on the hydration shell structure. On a micro level, the binding strength of the Na2+ counter ion is less than Ca2+, which is less than Mg2+, and this simulated result is consistent with the experimental results. The diffusion results can explain the interfacial tension (IFT) equilibrium time and have a significant effect on the optimal mixture method.

Key words: Molecular dynamics simulation, Electrolyte, Nonionic-anionic surfactant, Hydration shell, Interaction

MSC2000: 

  • O647