Adsorption of polycations on clays: A comparative in situ study using {sup 133}Cs and {sup 23}Na solution phase NMR
- Sheffield Hallam Univ. (United Kingdom). Materials Research Inst.
- Univ. of Sheffield (United Kingdom). Chemistry Dept.
{sup 23}Na solution phase NMR has been evaluated as an in situ probe to study the adsorption of tetramethylammonium (TMA{sup +}) and two polycations, FL17 and Magnafloc 1697, onto clays in aqueous suspensions containing 2.5 mass% low iron Texas bentonite. The NMR data shows the effectiveness of the organocations at displacing Na{sup +} from the bentonite surface. This information has been correlated with that obtained from particle-size and electrophoretic measurements in aqueous solution, together with information from adsorption isotherms. These results have been compared to those obtained in parallel studies using {sup 133}Cs solution phase NMR. FL17 and 1697 both exhibited high affinity adsorption isotherms on Na{sup +}- and Cs{sup +}-clay, whereas the adsorption of TMA{sup +}, which represents the cationic portion of the polymers was of lower affinity. Na{sup +}-bentonite adsorbed almost twice the amount of polycation required to fulfill the cation-exchange capacity (CEC) of the bentonite. The electrophoretic and particle size data indicated significant differences in the size of the polycation/clay flocs and the amount of polymer adsorbed on the external faces of the flocs in the presence of Na{sup +}- and Cs{sup +}-exchange ions. Correlation of this data with the NMR results suggests that the Na{sup +}-bentonite/polycation flocs are large, of low density, and that the polycation is concentrated in the interior while the Na{sup +}-ions occupy exchange sites on the external faces.
- OSTI ID:
- 556748
- Journal Information:
- Journal of Colloid and Interface Science, Vol. 193, Issue 2; Other Information: PBD: 15 Sep 1997
- Country of Publication:
- United States
- Language:
- English
Similar Records
Adsorption of benzene from aqueous solutions by bentonite treated with quaternary amines
Trimethylphenylammonium-Smectite as an effective adsorbent of water soluble aromatic hydrocarbons