Maghemite nanoparticles bearing di(amidoxime) groups for the extraction of uranium from wastewaters | INSTITUT DE PHYSIQUE DU GLOBE DE PARIS

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  Maghemite nanoparticles bearing di(amidoxime) groups for the extraction of uranium from wastewaters

Type de publication:

Journal Article

Source:

AIP Advances, Volume 7, Ticket 056702 (2017)

URL:

http://aip.scitation.org/doi/full/10.1063/1.4973436

Résumé:

<p>Polyamidoximes (pAMD) are known to have strong affinities for uranyl cations. Grafting pAMD onto the surface of functionalized maghemite nanoparticles (MNP) leads to a nanomaterial with high capacities in the extraction of uranium from wastewaters by magnetic sedimentation. A diamidoxime (dAMD) specifically synthesized for this purpose showed a strong affinity for uranyl: Ka = 10<sup>5</sup> M<sup>-1</sup> as determined by Isothermal Titration Calorimetry (nano-ITC). The dAMD was grafted onto the surface of MNP and the obtained sorbent (MNP-dAMD) was characterized. The nanohybrids were afterward incubated with different concentrations of uranyl and the solid phase recovered by magnetic separation. This latter was characterized by zeta-potential measurements, X-Ray Photoelectron Spectroscopy (XPS) and X-Ray Fluorescence spectroscopy (XRF), whereas the supernatant was analyzed by Inductively Coupled Plasma coupled to Mass Spectrometry (ICP-MS). All the data fitted the models of Langmuir, Freundlich and Temkin isotherms very well. These isotherms allowed us to evaluate the efficiency of the adsorption of uranium by MNP-dAMD. The saturation sorption capacity (qmax) was determined. It indicates that MNP-dAMD is able to extract up to 120 mg of uranium per gram of sorbent. Spherical aberration (Cs)-corrected High-Resolution Scanning Transmission Electron Microscopy (HRSTEM) confirmed these results and clearly showed that uranium is confined at the surface of the sorbent. Thus, MNP-dAMD presents a strong potential for the extraction of uranium from wastewaters.</p>