Acta Phys. -Chim. Sin. ›› 1995, Vol. 11 ›› Issue (09): 818-823.doi: 10.3866/PKU.WHXB19950911

• ARTICLE • Previous Articles     Next Articles

Phase Behavior of Aqueous Mixtures of Cationic-anionic Surfactants

Xiao Jin-Xin,Zhao Guo-Xi   

  1. Department of Chemistry,Peking University,Beijing 100871
  • Received:1994-10-12 Revised:1995-02-06 Published:1995-09-15
  • Contact: Zhao Guo-Xi


The phase behavior of the aqueous mixtures of C12H25N(CmH2m+1)3Br and CnH2n+1 OSO3Na (m=1,2,3,4. n=10,12) has been studied. It has been summarized that there exists commonly three concentration regions for the aqueous mixtures of cationicanionic surfactants. That is, the mixtures form homogeneous transparent solutions at low and high concentrations and heterogeneous region at mediate concentractions. It has shown that the ability forming homogeneous solutions for such systems increases with the increase of the sizes of polar groups and that of the effect of the length of hydrophobic moiety on the ability forming homogeneous solutions in high concentrations is not consistent completely with that in low concentrations, and sometimes the mixed system with short hydrophobic moiety has poorer ability forming homogeneous solutions than that with long hydrophobic moiety.

Key words: Cationic-anionic surfactants;Phase behavior