pH‐Switchable Cesium Nitrate Extraction with Calix[4]arene Mono and<i>bis</i>(Benzo‐crown‐6) Ethers Bearing Amino Functionalities

Bazelaire, Eve; Gorbunova, Maryna G.; Bonnesen, Peter V.; Moyer, Bruce A.; Delmau, Lætitia H.

doi:10.1081/sei-120039637

Cited by 22 publications

(13 citation statements)

References 12 publications

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“…Regarding the effect of adding the amino group, a comparison of BOBCalixC6 with AMBEHB shows a decrease in the extraction of cesium by a factor of 1.4 at AMBEHB and BOBCalixC6 concentrations of 2.5 mM in nitrobenzene. [6] Fig. 3 indicate that, at intermediate sodium nitrate concentrations, the cesium distribution ratio varies linearly (slope ¼ 0.99) for the acidic case (both axes in logarithmic scale).…”

Section: B Harmon Et Al 380mentioning

confidence: 90%

“…At high concentrations, for both the acidic and caustic measurements, a downturn in the D Cs was observed because of the decreasing activity coefficient of cesium at high aqueous salt concentrations. [6] A flat response of D Cs is observed below 0.1 M NaNO 3 at pH ¼ 12; as the aqueous nitrate concentration approaches the hydroxide concentration, the formation of the CsCalixOH species are significant. The values of D Cs under caustic conditions (Fig.…”

Section: B Harmon Et Al 380mentioning

confidence: 95%

“…[6] The ratio of D Cs was measured as a function of increasing [AMBEHB] from 0.25 mM to 2.5 mM in iso-octane containing 0.75 M Cs-7SB. The extractions were performed from either caustic (pH ¼ 12.0) or acidic (pH ¼ 2.0) media with the aqueous phases containing 1.0 M NaNO 3 and 10 24 M CsNO 3 .…”

Section: B Harmon Et Al 380mentioning

confidence: 99%

“…[5,6] It has been hypothesized that a charge-charge repulsion effect will destabilize the cesium complex upon protonating the amine group in the amino calixarene-crown compounds, thereby increasing D Cs , strip. Initial results indicated that the attachment of the amine group in the B.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Extraction of Cesium by a Calix[4]arene‐Crown‐6 Ether Bearing a Pendant Amine Group

Harmon

Ensor

Delmau

et al. 2007

Solvent Extraction and Ion Exchange

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Section: B Harmon Et Al 380mentioning

confidence: 90%

Section: B Harmon Et Al 380mentioning

confidence: 95%

Section: B Harmon Et Al 380mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Extraction of Cesium by a Calix[4]arene‐Crown‐6 Ether Bearing a Pendant Amine Group

Harmon

Ensor

Delmau

et al. 2007

Solvent Extraction and Ion Exchange

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“…Further extraction experiments with BEHBCalixC6, and with a derivative of BEHBCalixC6, which possesses an aminomethyl group substituted at the 5-position of the calix [4]arene, are described in a subsequent paper in this journal. [18] …”

Section: Synthesis Of Behbcalixc6 Extractant 633 Summary and Conclusionmentioning

confidence: 97%

Synthesis and Properties of Calix[4]arene‐bis[4‐(2‐ethylhexyl)benzo‐crown‐6], A Cesium Extractant with Improved Solubility

Engle

Bonnesen

Tomkins

et al. 2004

Solvent Extraction and Ion Exchange

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The new cesium-selective macrocycle calix [4]arene-bis [4-(2-ethylhexyl) benzo-crown-6] ("BEHBCalixC6") has been found to have improved solubility in a modified alkane diluent over calix [4]arene-bis(4-tert-octylbenzo-crown-6) ("BOBCalixC6"). The synthesis of this new calixcrown extractant, together with its solubility and extraction properties, is described in this report. The solubility, cesium extraction, and potassium loading behavior are compared with those of BOBCalixC6, the macrocycle currently employed in the caustic-side solvent extraction (CSSX) process for extracting cesium from alkaline nitrate solutions such as highlevel nuclear waste. Replacement of the tert-octyl alkyl chains on the benzo-crown portion of the calixcrown by 2-ethylhexyl chains improves the equilibrium solubility of the free calixcrown in aliphatic diluents while not affecting the cesium extraction strength. Equilibrium concentrations of BEHBCalixC6 in Isopar L diluent modified with 0.5 M 1-(2,2,3,3-tetrafluoropropoxy)-3-(4-sec-butylphenoxy)-2-propanol (Cs-7SB) over the course of 41 weeks of gentle agitation at 258C maintained the initial concentration of 57 + 2 mM, with no evidence of precipitation or thirdphase formation. In contrast, 57 + 2 mM solutions of BOBCalixC6 prepared using sonication were not stable, with precipitation occurring to afford an equilibrium concentration of only 6.7 + 0.2 mM after 41 weeks. Third-phase tests showed that BEHBCalixC6 resists third-phase formation as well as, or better than, BOBCalixC6. With increasing potassium loading from an alkaline sodium nitrate solution, both calixcrowns at 20 mM in modified Isopar L exhibited comparable onset of third-phase formation, gauging by the decreasing mass balance in cesium extraction from the same solutions. However, the BEHBCalixC6 solvent exhibited no visible indications of third-phase formation until the aqueous potassium concentration reached 0.75 M, whereas the BOBCalixC6 suffered visible third-phase formation when the aqueous potassium nitrate concentration reached 0.25 M. Calixcrowns with higher solubility in alkane diluents may find application in cesium extraction from waste matrices containing moderate (!0.2 M) quantities of potassium, such as that stored at the US Department of Energy's Hanford Site, where higher concentrations of the calixcrown extractant may be required to obtain practical cesium distribution coefficients for process flowsheets.

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The studies on absorption behavior of calix[4]-bis-crown-6 chromatographic resin and its application to the separation of HLW

Xin

Shu-ping

Deng

2012

J Radioanal Nucl Chem

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pH‐Switchable Cesium Nitrate Extraction with Calix[4]arene Mono andbis(Benzo‐crown‐6) Ethers Bearing Amino Functionalities

Cited by 22 publications

References 12 publications

Extraction of Cesium by a Calix[4]arene‐Crown‐6 Ether Bearing a Pendant Amine Group

Extraction of Cesium by a Calix[4]arene‐Crown‐6 Ether Bearing a Pendant Amine Group

Synthesis and Properties of Calix[4]arene‐bis[4‐(2‐ethylhexyl)benzo‐crown‐6], A Cesium Extractant with Improved Solubility

The studies on absorption behavior of calix[4]-bis-crown-6 chromatographic resin and its application to the separation of HLW

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