Kaolinite colloidal suspensions under the influence of sodium dodecyl sulfate

Abstract

Rheological properties of kaolinite particle suspensions in water were studied in the presence of sodium dodecyl sulfate (SDS). The characterization of slightly and strongly sonicated samples revealed the impact of particle initial clustering and agglomeration on their flow behavior; findings revealed that sonicated samples exhibit a stronger network. The influence of kaolinite concentration, sonication, and SDS loading on the apparent slip of kaolinite suspensions was also studied. The presence of SDS molecules prevents particle aggregation and network formation, which leads to a gradual reduction in yield stress. Through a suggested spatial hindrance mechanism, adding SDS above the minimum amount for micelle formation also stops network formation. Finally, it was found that increasing the concentration of kaolinite and sonication reduces the apparent slip, whereas increasing the surfactant concentration increases slip significantly. As a result of shear-induced migration, adding surfactant causes the interface to deplete and thus exhibit apparent slip.