Rheological Properties of Wormlike Micelles Formed by Cetyltrimethylammonium Bromide and Sodium Laurate

Abstract

Aqueous solutions of mixed cationic and anionic surfactants, cetyltrimethylammonium bromide (CTAB) and sodium laurate (SL), have been studied by steady-state rheology and dynamic oscillatory technique. Wormlike micelles can form due to attractive interactions between the oppositely charged headgroups of CTAB and SL. The wormlike micelles formed by CTAB/SL have been compared with that of cetylpyridinium bromide (CPB)/SL by steady-state rheology method. Effects of additional components such as NaBr, 1-propanol, 1-butanol, polyvinylpyrrolidone (PVP) on the micelles formation process have also been investigated. Cole-Cole plot has been applied to study the dynamic viscoelasticity of the wormlike micelles.

Keywords:

• Anionic surfactant
• cationic surfactant
• rheology
• wormlike micelles

Acknowledgments

The authors are grateful to the Excellent Young Scientist Awarded Fund (No. 2005BS08009) and the Technology Development Project (No. 2006GG2206004) of Shandong Province of China for financial support.