Induced asymmetries in the heteroaggregation of oppositely charged colloidal particles
| Autor: | F. J. de las Nieves, Antonio Fernandez-Barbero, Antonio M. Puertas |
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| Rok vydání: | 2003 |
| Předmět: |
Range (particle radiation)
Chemistry Concentration effect Ionic bonding Charged particle Surfaces Coatings and Films Electronic Optical and Magnetic Materials Biomaterials Colloid and Surface Chemistry Reaction rate constant Chemical physics Polymer chemistry Coagulation (water treatment) Static light scattering Surface charge |
| Zdroj: | Journal of Colloid and Interface Science. 265:36-43 |
| ISSN: | 0021-9797 |
| DOI: | 10.1016/s0021-9797(03)00349-7 |
| Popis: | Heterocoagulation of cationic and carboxylated polystyrene latexes is studied for a wide range of salt concentrations by static light scattering. The weak character of the surface groups providing the charges allows variation of the relative charge of the systems. Two situations are studied: both latexes with similar surface charges and with very different ones. In both cases at low ionic concentration pure heteroaggregation takes place, whereas diffusive aggregation is observed at high κ , above the critical coagulation concentration (C.C.C.) of both latexes. The overall rate of aggregation describes a minimum at intermediate salt concentrations when both latexes bear similar charges. The heterocoagulation rate constant decreases continuously to reach the diffusive value at high salt. An interesting behavior is observed when the latexes have very different charge. The heterocoagulation kinetic constant becomes diffusive above the C.C.C. of the less charged latex. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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