Viscosities of dilute aqueous suspensions of montmorillonite and kaolinite clays

Abstract

We have measured viscosities and densities of dilute aqueous suspensions of Na-kaolinite (2S°C), of Na-montmorillonite (25-5j°C), and of mixtures of Na-kaolinite/Na-montmorillonite (25°C). Results of the measurements at 25OC have been analyzed in terms of the Einstein equation with conclusions that are consistent with previous knowledge that colloidal particles of these clays are non-spherical and that montmorillonite is a swelling clay. Viscosities of mixed clay systems are nearly consistent with a simple additivity model; the small non-additivities are in accord with previous evidence that relatively small montmorillonite particles are adsorbed on the surface of relatively large kaolinite particles. The effect of temperature on the viscosities of suspensions of montmorillonite is consistent with the idea that aggregation of clay particles diminishes with increasing temperature.

Rheology of Dilute Suspensions of Hard Platelike Colloids

“…Worth mentioning in this respect is that the limited number of particles in a typical DPD box does not allow us to incorporate polydispersity in the simulation model. Bearing these effects in mind, the comparison with DPD appears to support the approximately hard-plate character of the experimental system, as the φ-dependence of the viscosity is generally observed to increase distinctly if other than hard-body interactions come into play (5,11,14).…”

“…For hard rods in the limit of zero shear rate, the value resulting from hydrodynamic pair-interactions was calculated by Berry and Russel (13) as 2/5. Experimental observations (5,11,14) suggest that the value of κ H grows considerably if other than hard-core interparticle interactions come into play.…”

“…Many industrial systems, however, contain anisometric particles, largely because of the natural abundance of clay platelets. The suitability of a clay suspension as a simple model system for plates is nevertheless severely limited by the polydispersity, swelling, and long-range interactions of the clay platelets (4,5). The existing lack of experiments on a hard (i.e., short-range repulsive) platelet model system is accompanied by a scarcity of theoretical work and simulations addressing the physical properties of platelike particles (6,7).…”

Rotational motion of a thin axisymmetric disk in a low Reynolds number linear flow

“…The above exact analytical result for f * y is compared with the regularized outer solution for f * y from (38). The results are found to be in good agreement and are shown in Figure 6 for κ = 10 −2 .…”

Determination of the Effects of a Bipolar Polypyridylosmium(II) Complex on the Stability of Montmorillonite Colloids

“…) (27,28). The refractive index and density of the colloidal particles are involved in calculating relatively modest corrections of the particle-size distribution.…”