Extraction of Zinc(ii) Ion by Didodecylnaphthalenesulfonic Acid (Hddns) in Carbon Tetrachloride: The Role of Aggregation

Lumetta, Gregg J.; Moyer, Bruce A.; Johnson, Paula A.; Wilson, N. M.

doi:10.1080/07366299108918048

Cited by 12 publications

(1 citation statement)

References 22 publications

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“…The indicated that extraction takes place through a micellartype mechanism, similar to other highly aggregated extraction systems, such as, dinonylnaphthalene-and didodecylnaphthalene-sulfonic acids [12][13][14], mono(2ethylhexyl) phosphoric acid [15][16][17] and quaternary alkylammonium salts [18], wherein cations are extracted into the core of the extractant aggregate.…”

Section: Extraction Equilibriamentioning

confidence: 88%

TEMPERATURE EFFECTS IN THE EXTRACTION OF METAL IONS BY DIALKYL-SUBSTITUTED DIPHOSPHONIC ACIDS. I. THE Am(III) CASE

Otu¹,

Chiarizia²

2001

Solvent Extraction and Ion Exchange

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The extraction of Am(III) from HNO 3 by o-xylene solutions of P,P 0 -di(2-ethylhexyl) methylene-(H 2 DEH[MDP]), ethylene-(H 2 DEH[EDP]), and butylene-(H 2 DEH[BuDP]) diphosphonic acids has been investigated. Thermodynamic parameters of the extraction process were determined by the temperature coefficient of the metal distribution ratio in the 25.0 to 60.0 C tem-SOLVENT EXTRACTION AND ION EXCHANGE, 19 (5), 885-904 (2001) 885 Published by Marcel Dekker, Inc. ORDER REPRINTS perature range. The extractant aggregation and the extraction stoichiometries with the different diphosphonic acids did not exhibit any significant temperature dependence. Extraction of Am(III) by H 2 DEH[MDP] is favored by both enthalpy and entropy variations. When Am(III) is extracted by either H 2 DEH[EDP] or H 2 DEH[BuDP] the process is entropy controlled. The enthalpy variation for Am(III) extraction exhibited a trend along the series H 2 DEH[MDP], H 2 DEH[EDP], H 2 DEH [BuDP], with the reaction being exothermic for the first, thermoneutral for the second, and endothermic for the third extractant, respectively. This trend was explained as arising from the formation of progressively less stable chelate rings along the diphosphonic acids series. The zero or positive enthalpy variation with a concomitant favorable entropy variation confirm for H 2 DEH[EDP] and possibly for H 2 DEH[BuDP] a micellar-like type of extraction process.

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