It is extremely desirable but challenging to develop exchange-coupled magnets with well-dispersed hard/soft phase and confined size to meet the high energy requirements of advanced magnets in modern industry and information technology. Here, we report a novel bottom-up strategy with two-step thermal decomposition and reductive annealing process to synthesize Nd₂Fe₁₄B/α-Fe nanocomposites, in which effective control of the hard/soft magnetic phase size and proportion was achieved. It is worth noting that the composition, as well as phase distribution, can be readily tuned by changing the ratio between Nd-Fe-B-oxide and α-Fe. This work provides an effective approach to adjust the phase size and distribution for exchange-coupled, rare-earth nanomagnets, which can be fundamental for high energy magnets.
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http://dx.doi.org/10.1039/c4nr02163k | DOI Listing |
ACS Omega
April 2024
Polymer Colloids & Nanomaterials Group, Department of Chemistry, Faculty of Science, University of Rajshahi, Rajshahi 6205, Bangladesh.
An alternative way for the coating of polypyrrole (PPy) polymer on hydrophobic magnetite (FeO) nanoparticles is reported here to capture toxic chromium ions, Cr (VI), present in water. Iron oxide magnetic nanoparticles (FeO) were synthesized by the conventional coprecipitation technique using FeCl·6HO and FeSO·7HO iron precursors and subsequently modified with oleic acid (OA). Then OA-FeO hydrophobic nanoparticles were oxidized using the Lemieux-von Rudloff reaction to transfer OA into hydrophilic azelaic acid (AA) (HOOC(CH)COOH-modified magnetic nanoparticles (AA-FeO).
View Article and Find Full Text PDFSoft Matter
March 2021
Department of Chemical Engineering, National Chung Hsing University, Taichung 402, Taiwan.
In this study, we report the dependence of the nanoparticle dispersion on the zero-conversion initiator efficiency in the nanocomposites formed by poly(N-vinyl carbazole) (PNVK) and acrylic acid-modified iron oxide (AA-FeO) nanoparticles via free radical solution polymerization of the precursor solution, that is, a thorough mixture of 28.5 wt% AA-FeO nanoparticles and the N-vinyl carbazole (NVK) monomer with the solvent dimethylformamide and azobisisobutyronitrile as an initiator. Here three different types of the dispersion state of AA-FeO nanoparticles in the PNVK matrix have been distinguished by a combined approach of transmission electron microscopy and small-angle X-ray scattering coupled with real-space models of the nanoparticle assemblies.
View Article and Find Full Text PDFMolecules
October 2019
Surfactant research chair, Chemistry department, college of science, King Saud University, Riyadh 11451, Saudi Arabia.
The ionic crosslinked 2-acrylamido-2-methylpropane sulfonic acid-co-acrylic acid hydrogel, AMPS/AA and its Ag and FeO composites were synthesized using an in situ technique. The surface charge, particle sizes, morphology, and thermal stability of the prepared AMPS/AA-Ag and AMPS/AA-FeO composites were evaluated using different analytical techniques and their adsorption characteristics were evaluated to remove the methylene blue cationic dye, MB, from their aqueous solutions at optimum conditions. Also, the same monomers were used to synthesize AMPS/AA microgel and its Ag and FeO nanocomposites, which were synthesized using the same technique.
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