title: Lanthanide sorbent based on magnetite nanoparticles functionalized with organophosphorus extractants.
abstract: In this work, an adsorbent was prepared based on the attachment of organophosphorus acid extractants, namely, D2EHPA, CYANEX 272, and CYANEX 301, to the surface of superparamagnetic magnetite (Fe3O4) nanoparticles. The synthesized nanoparticles were coated with oleic acid, first by a chemisorption mechanism and later by the respective extractant via physical adsorption. The obtained core-shell functionalized magnetite nanoparticle composites were characterized by dynamic light scattering, scanning electron microscopy, transmission electron microscopy, thermogravimetry, infrared absorption and vibrating sample magnetometry. All the prepared nanoparticles exhibited a high saturation magnetization capacity that varied between 72 and 46 emu g-1and decreased as the magnetite nanoparticle was coated with oleic acid and functionalized. The scope of this study also included adsorption tests for lanthanum, cerium, praseodymium, and neodymium and the corresponding analysis of their results. Sorption tests indicated that the functionalized nanoparticles were able to extract the four studied lanthanide metal ions, although the best extraction performance was observed when the sorbent was functionalized with CYANEX 272, which resulted in a loading capacity of approximately 12-14 mgLa/gMNP. The magnetization of the synthesized nanoparticles was verified during the separation of the lanthanide-loaded sorbent from the raffinate by using a conventional magnet.
authors.affiliation: Facultad de Ciencias Químicas y Farmacéuticas/Universidad de Chile, Santos Dumont 964, Independencia, Santiago, Chile.
authors.forename: Carlos
authors.initials: C
authors.lastname: Basualto
authors.affiliation: Facultad de Ciencias Químicas y Farmacéuticas/Universidad de Chile, Santos Dumont 964, Independencia, Santiago, Chile.
authors.forename: José
authors.initials: J
authors.lastname: Gaete
authors.affiliation: Facultad de Ciencias Químicas y Farmacéuticas/Universidad de Chile, Santos Dumont 964, Independencia, Santiago, Chile.
authors.forename: Lorena
authors.initials: L
authors.lastname: Molina
authors.affiliation: Facultad de Ciencias Químicas y Farmacéuticas/Universidad de Chile, Santos Dumont 964, Independencia, Santiago, Chile.
authors.forename: Fernando
authors.initials: F
authors.lastname: Valenzuela
authors.affiliation: Facultad de Ciencias Químicas y Farmacéuticas/Universidad de Chile, Santos Dumont 964, Independencia, Santiago, Chile.
authors.forename: Claudia
authors.initials: C
authors.lastname: Yañez
authors.affiliation: Instituto de Química-Física Rocasolano, CSIC, Calle Serrano 119, Madrid E-28006, Spain.
authors.forename: Jose F
authors.initials: JF
authors.lastname: Marco
keywords: functionalized magnetite sorbent; lanthanide metal; magnetite nanoparticles; organophosphorus extractant