Rheological investigation on anionic wormlike micelles at high temperature

Abstract

Rheological experiments were carried out on wormlike micelle formed by C22-tailed anionic surfactant sodium erucate (NaOEr) in the presence of KCl or tetramethyl ammonium bromide (TMAB). The effects of salt and surfactant concentration are systematically investigated at 80°C. Two kinds of salt-based micelle systems both maintain strong rheological properties at high temperature. By comparison, KCl–NaOEr system possesses lower critical overlapping concentration, stronger viscosity, and threshold salt concentration. Obviously, KCl shows high efficiency than TMAB in favoring micelle growth and improving the viscoelasticity of solution. The steric hindrance should be responsible for the inefficiency of TMAB compared to KCl. The extra-long hydrophobic chain of NaOEr is responsible for the desirable thermostability.