Investigation of imprinted sol-gel sorbents containing phosphonate ligands

Author

John Walter Clavier

Date of Award

12-2000

Degree Type

Thesis

Degree Name

Master of Science

Major

Chemistry

Major Professor

Craig E. Barnes

Committee Members

Douglass D. Gilman

Abstract

This thesis describes the development of sol-gel materials containing bifunctional phosphonate ligands for the extraction of Sr⁺² and UO₂⁺² from solution. Previous techniques developed for removing Sr⁺² and UO⁺² ions from aqueous solutions have focused on solvent extraction methods. The extraction technique proposed here utilizes mesoporous sol-gel containing functionalized areas of phosphonate bifunctional compounds of the form

≡SiCH₂CH₂CH₂P(O)(OEt)₂, (≡SiCH₂CH₂CH₂)₂C[P(O)(OEt)₂]₂, and ((≡SiCH₂CH₂CH₂P(O)(OEt)₂)₂(OCH₂CH₂O). By using a solid phase extraction sorbent, organic waste is minimized during the extraction process. The efficiency of Sr⁺² and UO₂⁺² ions extraction by these developed materials was investigated. Studies Found that Sr⁺² and UO₂⁺² did not absorb onto the phosphonate ester based ligand sorbents. Imprinted phosphonic acid based sorbents did exhibit high affinities for both Sr⁺² over nonimprinted phosphonic acid based sorbents. These studies also showed no selectivity between Sr⁺² and Ca⁺². As for UO₂⁺², there was no increase in affinity for U0₂⁺² between the imprinted and nonimprinted phosphonic acid based sorbents. However both sorbents showed selectivity between Ca⁺² and U0₂⁺². Finally, the imprinted phosphonic acid sorbents had fast kinetics and could be regenerated in 2.0 M HCI.

Recommended Citation

Clavier, John Walter, "Investigation of imprinted sol-gel sorbents containing phosphonate ligands. " Master's Thesis, University of Tennessee, 2000.
https://trace.tennessee.edu/utk_gradthes/9325