COLL 455 |
| John Y. Walz1, Pawel Weronski1, and Menachem Elimelech2. (1) Department of Chemical Engineering, Yale University, P. O. Box 208286, New Haven, CT 06520-8286, (2) Department of Chemical Engineering, Environmental Engineering Program, Yale University, PO Box 208286, New Haven, CT 06520-8286 |
| The effects of attractive depletion forces on the rate of transport of colloidal particles through a porous medium was measured using a packed column. In these experiments, a pulse of micron-sized latex particles was injected into a flowing solution upstream of a cylindrical column packed with glass beads. An attractive depletion force between the latex particles and glass beads was induced via the presence of nanometer-sized silica spheres in the flowing fluid (all surfaces were negatively charged). At sufficiently high silica concentrations, the depletion attraction could actually trap the latex particles in the bed. When the silica particles were removed from the solution, however, many of these trapped particles would be released, meaning that the particles were held in reversible, secondary energy wells. The results were found to be qualitatively consistent with predictions made using a force-balance model for calculating the interaction energy profile between a single spherical particle and a flat plate. |
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ACS Award in Colloid and Surface Chemistry Symposium Honoring Clay Radke
Division of Colloid and Surface Chemistry |