1. Solid Phase Extraction of Cesium from Aqueous Solution Using Sol-Gel Encapsulated Cobalt Hexacyanoferrate.
- Author
-
Vu Ca, Diep and Cox, James A.
- Subjects
COLLOIDS ,SILICON ,COAGULATION ,ALCOHOL ,SILICA ,PHYSICAL & theoretical chemistry - Abstract
The synthesis and evaluation of silica sol-gels doped with cobalt hexacyanoferrate (CoHCF) for solid phase extraction of Cs
+ from aqueous solution is described. The CoHCF is formed by first introducing K4 Fe(CN)6 (HCF) into the sol-gel and subsequently contacting the porous solid to a solution containing Co2+ . Generally, sols contain alcohol as a co-solvent, which limits the solubility of HCF. Inclusion of generation-4 polyamidoamine (G4-PAMAM) dendrimer in the sol-gel increases the level of HCF and, in turn, the CoHCF. The uptake capacity of this composite was 0.43±0.01 mmol Cs+ g-1 . A second approach to increasing the level of HCF silica is to exclude alcohol from the sol and use ultrasound to obtain a homogeneous suspension; HCF concentrations up to 0.17 M in the sol were thereby achieved. After gelation and reaction with Co2+ , the resulting composite had a capacity of 0.61±0.01 mmol Cs+ g-1 . With 0.5 mM Cs+ as the sample, the presence of either 0.5–100 mM Na+ or 10 mM Ca2+ did not change that value at the 95% confidence level. [ABSTRACT FROM AUTHOR]- Published
- 2004
- Full Text
- View/download PDF