Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (04): 913-917.doi: 10.3866/PKU.WHXB20110420

• SOFT MATTER • Previous Articles     Next Articles

Effect of Sodium Salicylate on the Formation and Properties of Wormlike Micelles in Aqueous Cationic Gemini Surfactant Solutions

PEI Xiao-Mei1, ZHAO Jian-Xi1, WEI Xi-Lian2   

  1. 1. Institute of Colloid and Interface Chemistry, College of Chemistry and Chemical Engineering, Fuzhou University, Fuzhou 350108, P. R. China;
    2. College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, Shandong Province, P. R. China
  • Received:2010-12-06 Revised:2011-01-26 Published:2011-03-29
  • Contact: ZHAO Jian-Xi, WEI Xi-Lian E-mail:jxzhao.colloid@fzu.edu.cn; weixilian@126.com
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20673021, 20873024, 21073081).

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Abstract:

The effect of sodium salicylate (NaSal) on the formation and properties of wormlike micelles in aqueous solutions of 2-hydroxyl-propanediyl-α,ω-bis(dimethyldodecylammonium bromide) (12-3(OH)-12) and propanediyl-α,ω-bis(dimethyldodecylammonium bromide) (12-3-12) at a surfactant concentration of 50 mmol·L-1 was investigated using steady-state and frequency sweep rheological measurements. In the absence of a salt, 12-3(OH)-12 or 12-3-12 only produced spherical or small rod-like micelles at 50 mmol·L-1. The addition of NaSal promoted micellar growth yielding wormlike micelles in both systems. 12-3(OH)-12 showed a more sensitive response to the added NaSal compared with 12-3-12 and formed wormlike micelles at relatively lower salt concentrations. Moreover, the wormlike micelles formed by 12-3(OH)-12 were longer than those formed by 12-3-12, resulting in higher viscosity for the former solution. These were attributed to the hydrogen bonding interactions between the hydroxyl substituted spacers in the 12-3(OH)-12 system, which increased hydration on the aggregate surface and stimulated the dissociation of counterions. The higher charge on the 12-3(OH)-12 micellar surface was strongly associated with Sal-, which led to a tighter packing of the surfactant molecules in the micelles and thus strengthened the intermolecular hydrogen bonding interactions and effectively reinforced the growth of the 12-3(OH)-12 micelles.

Key words: Cationic gemini surfactant, NaSal, Wormlike micelle, Rheological property, Intermolecular hydrogen bond

MSC2000: 

  • O648