Enhancing remote controlled heating characteristics in hydrophilic magnetite nanoparticles via facile co-precipitation

Citric acid coated magnetite nanoparticles were synthesized using a one-step and two-step coprecipitation method at different temperatures. The stability of the nanoparticles in aqueous media was compared. The magnetic heating characteristics in an alternating magnetic field we reexamined and specific absorption rates were determined. The nanoparticles were characterized by various techniques (Fourier transform infrared, UV spectrophotometry, thermogravimetric analysis, dynamic light scattering, transmission electron microscopy, X-ray diffraction and vibrating sample magnetometry). The temperature of synthesis and mode of functionalizing the particles affected their physical and magnetic properties. Higher temperatures led to increased specific absorption rates for both methods but more stable hydrophilic superparamagnetic nanoparticles were obtained in the one-step method. (C) 2009 Elsevier B.V. All rights reserved.