Facile green synthesis of nanomagnets for modulating magnetohyperthermia: tailoring size, shape and phase

作者：Silva, M. P.; Drummond, A. L.; Aquino, V. R. R.; Silva, L. P.; Azevedo, R. B.; Sales, M. J. A.; Morais, P. C.; Bakuzis, A. F.; Sousa, M. H.^*

来源：RSC Advances, 2017, 7(75): 47669-47680.

DOI：10.1039/c7ra09446a

• IRON-OXIDE NANOPARTICLES
• MAGHEMITE NANOPARTICLES
• MAGNETITE NANORODS
• HYPERTHERMIA TREATMENT
• COPRECIPITATION METHOD
• ALPHA-FE2O3 PARTICLES
• FERRITE NANOPARTICLES
• GROWTH
• TRANSFORMATION
• COLLOIDS

This study reports the successful production of both isometric and anisometric iron oxide-based nanoparticles using, respectively, ammonia and urea for co-precipitating Fe2+/Fe3+ from aqueous solution. Spherical nanoparticles (SNPs) with 10-20 nm in diameter are obtained using ammonia under reflux from 1 h to 9 h, with their relative magnetite/maghemite content decreasing from 10 to 0.05. However, using a lower and higher concentration of urea under reflux from 1 h to 12 h results in rod-like nanoparticles (RNPs) with length/width varying from 40/16 to 80/20 nm and hexagonal nanoparticles (HNPs) with diagonal varying from 150 to 100 nm, respectively. For RNPs (HNPs) the relative magnetite/goethite content increases with refluxing time from 0.25 to 2 (1.25 to 3.75). Hysteresis cycles (300 K) show unblocked SNPs and blocked RNPs and HNPs with coercivity (remanence) increasing with refluxing time from 55 to 80 Oe (1 to 5 emu g(-1)) and 70 to 130 Oe (5 to 13 emu g(-1)), respectively. Saturation magnetization of SNPs, RNPs and HNPs spans from 50 to 65 emu g(-1), 12 to 60 emu g(-1) and 57 to 80 emu g(-1), respectively. Under AC magnetic field (522 kHz), with amplitude ranging from 70 to 310 Oe, SNPs show a strong hyperthermia effect, following HNPs with mild and RNPs with weak effects.

• 出版日期2017
• 单位安徽大学