Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (05): 1026-1030.doi: 10.3866/PKU.WHXB20110503


The Second Virial Coefficient and Droplet Interaction of AOT/Water/Toluene Microemulsion

PENG Xu-Hong1, ZHENG Pei-Zhu2, MA Yuan-Ming1, YIN Tian-Xiang2, AN Xue-Qin2, SHEN Wei-Guo1,2   

  1. 1. Department of Chemistry, Lanzhou University, Lanzhou 730000, P. R. China;
    2. Department of Chemistry, East China University of Science and Technology, Shanghai 200237, P. R. China
  • Received:2010-12-27 Revised:2011-03-15 Published:2011-04-28
  • Contact: SHEN Wei-Guo
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20973061, 21073063).


Static light scattering measurements on a microemulsion of sodium bis(2-ethylhexyl) sulfosuccinate (AOT)/water/toluene with a water to AOT molar ratio of 12 at a series of temperatures and droplet concentrations were carried out to obtain their molecular weights, aggregation number, radius, and the second Virial coefficient of the droplets at various temperatures and concentrations. The dependence of the second Virial coefficient on the temperature was used to obtain the enthalpy and entropy of the interaction between the droplets, which were -4.03×104 J·mol-1 and -139.8 J·mol-1·K-1, respectively. These values indicate that the energy of surfactant penetration between the droplets in the AOT/water/toluene microemulsion system is negative and the penetration is driven by enthalpy.

Key words: Microemulsion, AOT, The second Virial coefficient, Droplet interaction, Static light scattering