Acta Phys. -Chim. Sin. ›› 2012, Vol. 28 ›› Issue (05): 1218-1222.doi: 10.3866/PKU.WHXB201202211

• SOFT MATTER • Previous Articles     Next Articles

Highly Viscoelastic Worm-Like Micelle Solution of Sodium Hexadecyl Sulfate Induced by Bolaform Counterions

ZHAO Jian-Xi, YANG Duo-Ping   

  1. Institute of Colloid and Interface Chemistry, Department of Applied Chemistry, College of Chemistry and Chemical Engineering, Fuzhou University, Fuzhou 350108, P. R. China
  • Received:2011-11-16 Revised:2012-02-01 Published:2012-04-26
  • Contact: ZHAO Jian-Xi E-mail:jxzhao.colloid@fzu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20673021, 20873024) and Natural Science Foundation of Fujian Province, China (2010J01038).

Abstract: The rheological behaviors of mixed aqueous solutions of sodium hexadecyl sulfate (SHS) and a bolaform salt, either N,N'-ethanediyl-α,ω-bis(ethyldimethylammonium bromide) (Bola2Et) or N,N'- propanediyl-α,ω-bis(trimethylammonium bromide) (Bola4), were investigated by steady-state and frequency-sweep measurements. The results showed that long worm-like micelles were formed in both systems at 45 °C, and the solutions exhibited high viscoelasticities, especially the SHS/Bola2Et system in which the solution had very high elasticity. The zero-shear viscosity of SHS/Bola2Et was as high as 2520 Pa·s, and the system was gel-like. These results were attributed to the formation of 2:1 complexes by electrostatic attraction. Since the spacers of both Bola counterions were shorter than the distance between quaternary ammonium ions under electrostatic equilibrium, the generated complex in shape favored formation of worm-like micelles. In comparison, it was difficult to induce SHS to form worm-like micelles by the addition of tetramethylammonium counterions, and the solution exhibited low viscosity.

Key words: Anionic surfactant, Bola-counterion, Worm-like micelle, High viscoelasticity

MSC2000: 

  • O646