Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (07): 1534-1540.doi: 10.3866/PKU.WHXB201304252

• SOFT MATTER • Previous Articles     Next Articles

A Highly Viscoelastic Anionic Wormlike Micellar System

XIE Dan-Hua1, ZHAO Jian-Xi1, LIU Lin1, YOU Yi1, WEI Xi-Lian2   

  1. 1 Institute of Colloid and Interface Chemistry, College of Chemistry and Chemical Engineering, Fuzhou University, Fuzhou, Fujian, 350108, P. R. China;
    2 Department of Chemistry, College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng, Shandong, 252059, P. R. China
  • Received:2013-02-04 Revised:2013-04-24 Published:2013-06-14
  • 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 (20873024, 21273040).

Abstract:

The rheological behavior of carboxylate gemini surfactant O,O'-bis(sodium 2- tetradecylcarboxylate)-p-dibenzenediol (referred to as C14Φ2C14) with a concentration of 140 mmol·L-1 in aqueous solution in the presence of 100 mmol·L-1 NaBr was investigated by frequency sweep and steady rate sweep measurements. The solution showed the characteristics of a Maxwell fluid with a single stress relaxation time at low shear frequencies. Analysis by the living polymer model indicated that C14Φ2C14 formed long (3.6-6.8 μm) wormlike micelles at 25℃, which were observed by cryo-transmission electron microscopy (cryo-TEM). The micelles were entangled with each other, resulting in a very viscous solution (the zero-shear viscosity was as high as 1.10×104 Pa·s) that looked like a gel. On raising the temperature to 70℃, the relative viscosity was still as high as 1.8×104, which is very rare for anionic wormlike micelle systems. The flow activation energy (Ea) was estimated to be (141±5) kJ·mol-1. The size distribution of C14Φ2C14 was determined by dynamic light scattering. Large aggregates with a size of ~100 nm were observed at low concentrations of 5-10 mmol·L-1. These large aggregates readily transformed into rodlike and then wormlike micelles as the surfactant concentration increased.

Key words: Carboxylate gemini surfactant, p-Dibenzenediol spacer, Wormlike micelle, High viscoelasticity, Temperature effect, Micelle formation mechanism

MSC2000: 

  • O648