Thixotropy and slip of kaolinite hybrid suspensions in the presence of surfactants

Abstract

In this paper, the behavior of Kaolinite suspensions is explored in the presence of two ionic surfactants, namely, cetyl trimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate (SDS). The steady-shear behavior of these suspensions is explored above and below the critical micelle concentration. The yield stress was found to increase monotonically with CTAB concentration, which can be explained by improved network strength. On the other hand, the yield stress was initially decreased with an increase in SDS concentration up to 10 mM with subsequent relatively small increase at higher concentrations. Both kaolinite and kaolinite-CTAB systems were found to exhibit thixotropic and anti-thixotropic behavior at short and long timescales, respectively.