The objective of this study was to better understand the kinetics of competitive deposition between polyelectrolyte-coated particles and polyelectrolyte molecules occurring simultaneously on the same surface. / In the study with cationic polyethylenimine (PEI), increasing the polyelectrolyte concentration showed six regimes of particle deposition. In the first regime, no particle deposition was observed, since the quantity of adsorbed polyelectrolyte was less than sufficient to create an electrostatic attraction between the partly coated particle and the surface. In the second regime, a fast rate of deposition is observed, where all of the PEI is adsorbed for complete coverage of particles except for a very small concentration in solution. In the third regime, initially fast deposition is followed by a slowing down of the rate until no deposition occurs due to a competition between free PEI in solution with coated particles for sites at the surface. In the fourth regime, no deposition is observed, since the concentration of PEI is high enough to adsorb extremely quickly using up all the surface sites available, reversing their charge to positive, repelling coated particles. In the fifth regime, slow deposition is observed, since high PEI concentrations screen the electrostatic repulsion. In the sixth regime, no deposition is observed possibly due to steric stability. / In the study with an anionic polyelectrolyte, NaPSS (sodium polystyrenesulphonate), it was shown that the equilibrium adsorption was independent of molecular weight for molecular weights of 18,000 to 220,000. For these molecular weights, no conditions for sufficient electrostatic or steric repulsion between fully-coated particles and the surface was obtained to prevent deposition. The deposition is ascribed to the small polyelectrolyte layer thickness on TiO$ sb2$ and the collector surface, as well as electrostatic screening by salt. (Abstract shortened by UMI.)
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.22747 |
| Date | January 1994 |
| Creators | Kelemen, S. J. (Susan J.) |
| Contributors | Ven, T. G. M. van de (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Chemistry.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001445248, proquestno: MM05570, Theses scanned by UMI/ProQuest. |
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