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Title: Extraction of Cesium by a Calix[4]arene-Crown-6 Ether Bearing a Pendant amine Group

Abstract

The goal of this work was to evaluate the role of the amino group of 5-aminomethylcalix[4]arene-[bis-4-(2-ethylhexyl)benzo-crown-6] (AMBEHB) in the extraction of cesium from acidic and basic mixtures of sodium nitrate and other concentrated salts. The extraction of cesium from nitrate media was measured as a function of extractant concentration, nitrate concentration, cesium concentration, and pH over the range 1-13. The initial studies showed a moderate decrease in the extraction of cesium in acidic media, which indicated the binding of cesium by the calixarene-crown was weakened by the protonation of the amine group. The results also indicated that a 1:1:1 Cs-ligand-nitrate complex is formed in the organic phase. To further evaluate AMBEHB, the empirical data were mathematically modeled to determine the formation constants of the complexes formed in the organic phase. The resulting formation constants showed that the attachment of the amine group to the calixarene-crown molecule reduced the binding stability for the cesium ion upon contact with an acidic solution. This supports the hypothesis of charge repulsion as the basis for more efficient stripping of cesium via pH-switching.

Authors:
 [1];  [1];  [2];  [2]
  1. Tennessee Technological University
  2. ORNL
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
931688
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Solvent Extraction and Ion Exchange; Journal Volume: 25; Journal Issue: 3
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; AMINES; BEARINGS; CESIUM; CESIUM IONS; ETHERS; HYPOTHESIS; MIXTURES; NITRATES; SODIUM NITRATES; STABILITY

Citation Formats

Harmon, Ben, Ensor, Dale, Delmau, Laetitia Helene, and Moyer, Bruce A. Extraction of Cesium by a Calix[4]arene-Crown-6 Ether Bearing a Pendant amine Group. United States: N. p., 2007. Web. doi:10.1080/07366290701285348.
Harmon, Ben, Ensor, Dale, Delmau, Laetitia Helene, & Moyer, Bruce A. Extraction of Cesium by a Calix[4]arene-Crown-6 Ether Bearing a Pendant amine Group. United States. doi:10.1080/07366290701285348.
Harmon, Ben, Ensor, Dale, Delmau, Laetitia Helene, and Moyer, Bruce A. Mon . "Extraction of Cesium by a Calix[4]arene-Crown-6 Ether Bearing a Pendant amine Group". United States. doi:10.1080/07366290701285348.
@article{osti_931688,
title = {Extraction of Cesium by a Calix[4]arene-Crown-6 Ether Bearing a Pendant amine Group},
author = {Harmon, Ben and Ensor, Dale and Delmau, Laetitia Helene and Moyer, Bruce A},
abstractNote = {The goal of this work was to evaluate the role of the amino group of 5-aminomethylcalix[4]arene-[bis-4-(2-ethylhexyl)benzo-crown-6] (AMBEHB) in the extraction of cesium from acidic and basic mixtures of sodium nitrate and other concentrated salts. The extraction of cesium from nitrate media was measured as a function of extractant concentration, nitrate concentration, cesium concentration, and pH over the range 1-13. The initial studies showed a moderate decrease in the extraction of cesium in acidic media, which indicated the binding of cesium by the calixarene-crown was weakened by the protonation of the amine group. The results also indicated that a 1:1:1 Cs-ligand-nitrate complex is formed in the organic phase. To further evaluate AMBEHB, the empirical data were mathematically modeled to determine the formation constants of the complexes formed in the organic phase. The resulting formation constants showed that the attachment of the amine group to the calixarene-crown molecule reduced the binding stability for the cesium ion upon contact with an acidic solution. This supports the hypothesis of charge repulsion as the basis for more efficient stripping of cesium via pH-switching.},
doi = {10.1080/07366290701285348},
journal = {Solvent Extraction and Ion Exchange},
number = 3,
volume = 25,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}