The influence of cationic surfactants on rheological properties of bentonite–water systems

Abstract

Abstract The influence of surfactants on the flow behaviour of bentonite–water systems (2% w/w) was studied for two cationic surfactants, cetyltrimethylammonium bromide (CTAB) and distearlydimethylammonium chloride (DDAC), in the range of 10 −5 –10 −2 mol/l. These surfactants were added to Ca- and Na-bentonite–water systems in seven different concentrations and the observed result was the different effects on the viscosity, which is related to the interactions between particles and surfactant, particles and particles, and particles and water molecules. The adsorption of cationic surfactant on a charged surface leads to significant modification of the charge distribution in the electrical double layer, and, thus, in the interaction of particles with each other.