WATER-DISPERSIBLE MAGNETITE NANOPARTICLES OBTAINED BY CO-PRECIPITATION AND THERMAL DECOMPOSITION METHODS.
Water-dispersible magnetite (Fe3O4) nanoparticles were synthesised by the co-precipitation of iron salts (dual-source) and the hot injection thermolysis of iron pivalate complex (single source). The iron pivalate complex was thermolysed in a mixture of polyvinylpyrrolidone (PVP) as capping agent and triethylene glycol (TREG) as solvent at the boiling point of the solvent (285 °C). The co-precipitation method involved precipitating iron(II) and iron(III) salts with ammonium hydroxide at room temperature. This was then followed by the addition of polyallylamine hydrochloride (PAH). The p-XRD patterns obtained for the nanoparticles revealed that magnetite was synthesised by both methods. TEM showed that the magnetite nanoparticles obtained from the thermal decomposition method are more monodispersed (4.1 ± 0.3 nm) than those obtained from co-precipitation method (7.0 ± 1.0 nm). The nanoparticles were characterised by powder X-ray diffraction (p-XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED).