Abstract

A facile and fast microwave-assisted hydrothermal method is proposed for the synthesis of magnetitenanoparticles. The addition of different surfactants (polyvinylpyrrolidone, oleic acid, or trisodium citrate)was studied to investigate the effect on size distribution, morphology, and functionalization of themagnetite nanoparticles. Microwave irradiation at 150 °C for 2 h of aqueous ferrous chloride andhydrazine without additives results in hexagonal magnetite nanoplatelets with a facet-to-facet distance of116 nm and a thickness of 40 nm having a saturation magnetization of ~65 Am2 kg-1. The use ofpolyvinylpyrrolidone led to hexagonal nanoparticles with a facet-to-facet distance of 120 nm and athickness of 53 nm with a saturation magnetization of ~54 Am2 kg-1. Additives such as oleic acid andtrisodium citrate yielded quasi-spherical nanoparticles of 25 nm in size with a saturation magnetization of~70 Am2 kg-1 and spheroidal nanoparticles of 60 nm in size with a saturation magnetization up to~82 Am2 kg-1, respectively. A kinetic control of the crystal growth is believed to be responsible for thehexagonal habit of the nanoparticles obtained without additive. Conversely, a thermodynamic control ofthe crystal growth, leading to spheroidal nanoparticles, seems to occur when additives which stronglyinteract with the nanoparticle surface are used. A thorough characterization of the materials wasperformed. Magnetic properties were investigated by Superconducting Quantum Interference Device andVibrating Sample Magnetometer. Based on the observed magnetic properties, the magnetite obtained usingcitrate appears to be a promising support for magnetically transportable catalysts.

Autore Pugliese

• Caliandro Rocco

Tutti gli autori

• Rizzuti A.; Dassisti M.; Mastrorilli P.; Sportelli M.C.; Cioffi N.; Picca R.A.; Agostinelli E.; Varvaro G.; Caliandro R.

Titolo volume/Rivista

Journal of nanoparticle research

Anno di pubblicazione

2015

ISSN

1388-0764

ISBN

Non Disponibile

Numero di citazioni Wos

Nessuna citazione

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Numero di citazioni Scopus

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Settori ERC

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Codici ASJC

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