Structural Transitions in Colloidal Suspensions
In suspensions of colloidal particles different types of interactions are in a subtle interplay. In this report we are interested in sub-micro meter sized Al2O3 particles which are suspended in water. Their interactions can be adjusted by tuning the pH-value and the salt concentration. In this manner different microscopic structures can be obtained. Industrial processes for the production of ceramics can be optimized by taking advantage of specific changes of the microscopic structure. To investigate the influences of the pH-value and the salt concentration on the microscopic structure and the properties of the suspension, we have developed a coupled Stochastic Rotation Dynamics (SRD) and Molecular Dynamics (MD) simulation code. The code has been parallelized using MPI. We utilize the pair correlation function and the structure factor to analyze the structure of the suspension. The results are summarized in a stability diagram. For selected conditions we study the process of cluster formation in large scale simulations of dilute suspensions.
KeywordsIonic Strength Shear Rate Colloidal Particle Cluster Formation Colloidal Suspension
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- 11.B. V. Derjaguin and L. D. Landau. Theory of the stability of strongly charged lyophobic sols and of the adhesion of strongly charged particles in solutions of electrolytes. Acta Phsicochimica USSR, 14:633, 1941.Google Scholar
- 15.M. J. Grimson and M. Silbert. A self-consistent theory of the effective interactions in charge-stabilized colloidal dispersions. Macromol. Phys., 74(2):397–404, 1991.Google Scholar
- 18.M. Hecht, J. Harting, and H. J. Herrmann. Formation and growth of clusters in colloidal suspensions. Int. J. Mod. Phys. C, 2007. in print.Google Scholar
- 19.M. Hecht, J. Harting, and H. J. Herrmann. A stability diagram for dense suspensions of model colloidal al2o3-particles in shear flow. arXiv:cond-mat/0606455, 2006. Accepted for publication in Phys. Rev. E.Google Scholar
- 21.M. Hütter. Brownian Dynamics Simulation of Stable and of Coagulating Colloids in Aqueous Suspension. PhD thesis, Swiss Federal Institute of Technology Zurich, 1999.Google Scholar
- 27.A. Komnik, J. Harting, and H. J. Herrmann. Transport phenomena and structuring in shear flow of suspensions near solid walls. Journal of Statistical Mechanics: theory and experiment, P12003, 2004.Google Scholar
- 37.R. Oberacker, J. Reinshagen, H. von Both, and M. J. Hoffmann. Ceramic slurries with bimodal particle size distributions: Rheology, suspension structure and behaviour during pressure filtration. In N. C. S. Hirano, G.L. Messing, editor, Ceramic Processing Science VI, volume 112, pages 179–184. American Ceramic Society, Westerville, OH (USA), 2001. ISBN 1574981048.Google Scholar
- 46.A. Sierou and J. F. Brady. Shear-induced self-diffusion in non-colloidal suspensions. J. Fluid Mech., 506:285, 2004.Google Scholar
- 52.E. J. W. Vervey and J. T. G. Overbeek. Theory of the Stability of Lyophobic Colloids. Elsevier, Amsterdam, 1948.Google Scholar
- 54.R. Yamamoto, K. Kim, Y. Nakayama, K. Miyazaki, and D. R. Reichman. On the role of hydrodynamic interactions in colloidal gelation. arXiv:cond-mat/0604404, 2006.Google Scholar