Magnetic behavior of superparamagnetic nanoparticles containing chelated transition metal ions

Author(s)

Melo, Fernando M. ^[1] ; Silveira, Alceu T. ^[1] ; Quartarolli, Lucas F. ^[1] ; Kaid, Felipe F. ^[1] ; Cornejo, Daniel R. ^[2] ; Toma, Henrique E. ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Quim, Sao Paulo, SP - Brazil

^[2] Univ Sao Paulo, Inst Fis, Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: Journal of Magnetism and Magnetic Materials; v. 487, OCT 1 2019.
• Web of Science Citations: 1

Abstract

Superparamagnetic nanoparticles functionalized with diethylenetriaminepentaacetic acid (MagNP@DTPA) have been employed for extracting and processing strategic metal ions in nanohydrometallurgy. In order to probe the metal ion capture from aqueous solution in real time, an external weighing device has been adapted for a conventional analytical balance, allowing to measure the nanoparticles attraction by a miniature neodymium (Nd2Fe14B) supermagnet. The magnetic migration kinetics, also referred as magnetophoresis, has been probed in this way, as well as the evaluation of the magnetic interaction of the Fe3O4 core with the attached paramagnetic metal ions. The results indicated some correlation between the overall nanoparticle magnetic moments and their magnetophoretic rates. An additive magnetic response was observed for the metallated nanoparticles in dry form, using VSM. However, in solution, the global magnetization decreased with the magnetic moment of the attached metal ions. Presumably, there is an influence of dipolar and superexchange interactions mediated by the metal-ligand structures, including the formation of carboxylate bridges between the outer paramagnetic centers in the dry form. (AU)

• FAPESP's process: 13/24725-4 - Supramolecular chemistry and nanotechnology
• Grantee: Henrique Eisi Toma
• Support Opportunities: Research Projects - Thematic Grants