Shear Viscosity of Clay-like Colloids: Computer Simulations and Experimental Verification
نویسندگان
چکیده
Dense suspensions of small strongly interacting particles are complex systems, which are rarely understood on the microscopic level. We investigate properties of dense suspensions and sediments of small spherical Al2O3 particles in a shear cell by means of a combined Molecular Dynamics (MD) and Stochastic Rotation Dynamics (SRD) simulation. We study structuring effects and the dependence of the suspension’s viscosity on the shear rate and shear thinning for systems of varying salt concentration and pH value. To show the agreement of our results to experimental data, a relation between bulk pH value and surface charge of spherical colloidal particles is obtained within Debye-Hückel theory in conjunction with a 2pK charge regulation model. PACS numbers: 82.70.-y 47.11.+j, 02.70.Ns
منابع مشابه
Alignment of particles in sheared viscoelastic fluids.
We investigate the shear-induced structure formation of colloidal particles dissolved in non-Newtonian fluids by means of computer simulations. The two investigated visco-elastic fluids are a semi-dilute polymer solution and a worm-like micellar solution. Both shear-thinning fluids contain long flexible chains whose entanglements appear and disappear continually as a result of Brownian motion a...
متن کاملShear viscosity of claylike colloids in computer simulations and experiments.
Dense suspensions of small strongly interacting particles are complex systems that are rarely understood on the microscopic level. We investigate properties of dense suspensions and sediments of small spherical Al2O3 particles in a shear cell by means of a combined molecular-dynamics and stochastic rotation dynamics simulation. We study structuring effects and the dependence of the suspension's...
متن کاملFriction between brush layers of charged and neutral bottle-brush macromolecules. molecular dynamics simulations.
Using molecular dynamics simulations, we study the lubricating properties of neutral and charged bottle-brush coatings as a function of the compression and shear stresses and brush grafting density. Our simulations have shown that in charged bottle-brush systems under shear there is a layer with excess counterions located in the middle between brush-bearing surfaces. The main deformation mode o...
متن کامل0 Nonequilibrium thermodynamics of colloids
The common rules of classical nonequilibrium thermodynamics do not allow an Onsager coefficient like the viscosity to depend on the shear rate. Such a dependence is experimentally well documented, however. In this paper it is shown, using nonequilibrium thermodynamics alone, how it is possible that the effective viscosity coefficient of an isotropic colloidal system depends on both the shear ra...
متن کاملShear Viscosity of Strongly-coupled Two-dimensional Yukawa Liquids: Experiment and Modeling
This paper reviews experimental and modeling efforts aimed at the determination of the shear viscosity of strongly-coupled Yukawa liquids. After briefly reviewing prior work on three-dimensional (3D) systems, recent experimental and computer simulation studies of two-dimensional (2D) settings are presented in detail. In the experiments two counterpropagating laser beams were used to perturb a d...
متن کامل