CRCU

Chemical Research in Chinese Universities ›› 2004, Vol. 20 ›› Issue (1): 92-98.

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An Investigation of Structure Transition in Sodium Dodecyl Trioxyethylene Sulfate/n-Butanol/n-Octane/Water System by Dielectric Relaxation Spectroscopy Method

MU Jian-hai1, ZHAO Kong-shuang2, WEI Su-xiang3, LI Ying3, LI Gan-zuo1   

  1. 1. Key Laboratory for Colloid & Interface Chemistry of State Education Ministry, Shandong Uinversity, Jinan 250100, P. R. China;
    2. Department of Chemistry, Beijing Normal University, Beijing 100875, P. R. China;
    3. Department of Chemistry, South China Normal University, Guangzhou 510631, P. R. China
  • Received:2003-02-22 Online:2004-02-24 Published:2011-08-06
  • Supported by:

    Supported by the Visiting Scholor Foundation of Key Lab in Chinese University and the National Natural Science Foundation of China(No.20273010, 29873015).

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Abstract: The phase diagram of the quaternary system of sodium dodecyl trioxyethylene sulfate(SDES)/n-butanol/n-octane/water was obtained at (30.0±0.1) ℃. There exists a clear, isotropic, and low-viscosity L phase, which can be divided into W/O, bi-continuous(B.C.) and O/W microemulsions by conductivity measurement results. Dielectric Relaxation Spectroscopy(DRS) measurements, including permittivity, conductivity, relaxation strength, characteristic relaxation time, dielectric parameters, phase parameters, etc., were applied to investigating the microstructures of the system mentioned above. For the samples with a fixed SDES/n-butanol mass ratio of 4/6 including 20%(mass fraction) of n-octane, DRS indicated a structure transition from a W/O to an O/W via a B.C. microemulsion with the increase of the water content. For the samples with a fixed (SDES/20%n-octane)/H2O mass ratio of 5/5, DRS presented that there only exists a onefold structure of a W/O microemulsion as the (n-butanol/20%n-octane) content increases. The results obtained from DRS are in good agreement with those from the phase diagram.

Key words: Phase behavior, Conductivity, Dielectric relaxation spectroscopy, Microemulsion