Diglycolamic acid anchored on polyamine matrix for the mutual separation of Eu(III) and Am(III)

Abstract

Diglycolamic acid was anchored on a polyamine matrix and the product (PA-DGAH) was characterized by ion-exchange capacity measurement, TG-DTA and FT-IR spectroscopy. The extraction behavior of Am(III) and Eu(III) in PA-DGAH was studied from dilute nitric acid medium to examine the feasibility using the anchored adsorbent for their mutual separation. The effect of various parameters such as the duration of equilibration, concentration of europium, nitric acid and diethylenetriaminepentaacetic acid (DTPA) in aqueous phase on the distribution coefficient ( d ) of Am(III) and Eu(III) was studied.The distribution coefficient decreased with increase in the concentration of nitric acid. Rapid extraction of metal ions in the initial stages of equilibration followed by the establishment of equilibrium occurred within 4 h. The data on the rate of uptake of Am(III) and Eu(III) were fitted into pseudo-first order and pseudo-second order rate equation. The extraction isotherm was fitted to Langmuir and Freundlich adsorption models and the apparent europium extraction capacity was determined. The mechanism of extraction was elucidated and the conditions needed for efficient separation of Am(III) from Eu(III) was optimized using DTPA. The study indicated the possibility of using PA-DGAH for the separation of Eu(III) from Am(III) with high separation factors.

Extraction and recovery of rare earths by chelating phenolic copolymers bearing diglycolamic acid or diglycolamide moieties

“…To overcome such drawbacks, the extractant can be chemically anchored to the solid support. A literature survey show that diglycolamides and diglycolamic acid extractants have been grafted on polyamide matrix, 19 in a filmtype adsorbent, 20 as well as on silica gel particles, 21,22,23 mesoporous silica, 24,25 and oxide particles. 26 Interestingly, to the best of our knowledge, there is no evidence in the literature of the use of phenolic resin with incorporation of diglycolamides derivatives for REEs extraction.…”

Diglycolamic Acid-Functionalized MWCNT-Augmented Polymeric Beads for Efficient Separation of Trivalent Lanthanides and Actinides

“…The FTIR spectra of the pristine beads and those containing the PS-DGA-CNT beads are presented in Figure a. Although most of the spectra were consistent with those of pristine polysulfone beads due to the small DGA-CNT content, a characteristic peak for the carbonyl group (>CO) was observed at 1665 cm –1 . − Also, the peak increased with increasing load of DGA-CNTs in polysulfone. Furthermore, the −OH bending peak for carboxylic acid was also observed at 1405 cm –1 . − The observations confirm the incorporation of DGA-CNTs into the polysulfone polymeric beads.…”

“…Since oxygen is a hard donor that needs to be coordinated with the metal ions, it would exhibit a preference for Eu 3+ (hard−hard acid−base interaction). 26 Hence, the extraction efficiency for Am 3+ is supposed to be poorer compared to that of Eu 3+ . The binding of metal ions with DGA takes place via three oxygen atoms of DGA with the coordinated metal ion and three oxygen atoms of DGA lying in the same plane.…”

“…Eu 3+ is a harder acid compared to Am 3+ due to the participation of less-defused 4f orbitals of Eu (compared to the more-defused 5f orbital of Am). Since oxygen is a hard donor that needs to be coordinated with the metal ions, it would exhibit a preference for Eu 3+ (hard–hard acid–base interaction) . Hence, the extraction efficiency for Am 3+ is supposed to be poorer compared to that of Eu 3+ .…”

Covalent grafting of Diglycolamide functionalities over Merrifield resin for the uptake of trivalent f-block metal ions from acidic aqueous feed

“…Even though inert adsorbents with loaded extractants have shown better KD values than solvent extraction as proved by many researchers [47][48][49] they face the problem of leaching and can't be used multiple times. It is always better to covalently graft the functional groups to maintain consistency and reusability [50][51][52][53]. One of the basic difference between solvent extraction and adsorption is that in solvent extraction solute from aqueous phase first enters the organic phase and then interacts with the ligand.…”