A. Alemdar

The viscosity and zeta potential of bentonite dispersions in presence of anionic surfactants

Abstract The influence of surfactants on the flow behaviour of bentonite dispersions (2% w/w) is studied for two anionic surfactants, sodium dodecyl sulfate (SDS) and ammonium lauryl sulfate (ALS). In the range of 10 −4 –10 −2 mol/l, the surfactants show different effects on the viscosity and zeta potential of the bentonite suspension. The experimental results are discussed considering changes in the interlayer of the clay minerals.

The effect of SDS surfactant on the flow and zeta potential of bentonite suspensions

Abstract The influence of the surfactant on the flow behaviour of bentonite suspensions (2% w/w) was studied for an anionic surfactant, sodium dodecyl sulphate (SDS). In the range of 10 −4 –10 −2 mol/l, SDS was added to the bentonite water system in eight different concentrations and the observed result was the different effects on the viscosity, which is related to the interactions among particles and surfactant, particles and particles, and particles and water molecules. IR studies have been carried out in parallel to the viscosity and zeta potential studies. Based on the structural changes due to the SDS additions, the rheological and colloidal properties of the altered bentonite–water systems have been interpreted.

Effects of polyethyleneimine adsorption on rheology of bentonite suspensions

The influence of the cationic polymer, polyethyleneimine polymer (PEI) on the flow behaviour of bentonite suspensions (2%, w/w), was studied. XRD, zeta potential and adsorption studies were done together with rheological measurements. The addition of PEI at concentration ranges of 10-5-4.5 g/l and their rheological properties and stability of bentonite suspensions were studied. The adsorption rates for the bentonite suspensions are very fast. The XRD results showed that the PEG molecules did not intercalate into the layers of the clay.

Influences of Electrolytes, Polymers and a Surfactant on Rheological Properties of Bentonite–Water Systems

Characteristic rheological properties, such as viscosity, shear stress, yield point, gel strength and thixotropy, of natural Ca- bentonite and Na-peptized bentonite were studied after adding LiCl, KCl, CaCl2, MgCl2·6H2O electrolytes; (NaPO3)n, polyvinyl pyrolidone (PVP) polymers and an anionic surfactant (linear alkyl benzene sulphonate, LABS). Changes in flow properties under the influence of various additives at different quantities were investigated in these slurries. The experimental results are discussed in terms of bentonite forms, types and concentrations of additives and influence of exchangeable cations. Bivalent and monovalent cations display entirely different rheological properties in two groups of muds. Furthermore, the difference in the degree of activity of PVP polymer on the viscosity of two mud systems depend on the clay mineral structure. The slurry prepared with Na-bentonite contains a minimum number of tactoids and a maximum number of sheet-bearing clay particles, which reduces the surface area of the clay minerals and increases viscosity by adding PVP polymer.

By particle interactions and rheological properties of bentonites+ALS suspensions

Abstract The influence of an anionic surfactant, ammonium lauryl sulfate (ALS), on the flow behaviour and colloidal properties of bentonite suspensions (2% w/w) was studied with two objectives. The first one was to determine the rheological properties of three types of bentonite–water systems: two of which were prepared using natural Ca- and Na-bentonites, and the other one from soda-activated bentonite. The second objective was to describe the particle interactions of the three types of bentonite with ALS in the concentration range of 10 −4 –10 −2 mol/l.