Heating characteristics of dextran modified magnetite nanoparticles by infrared thermography

Magnetite nanoparticles were synthesized using co-precipitation and oxidation methods with average particle sizes of 12 and 60 nm respectively. Dextran coated magnetite nanoparticles were synthesized using oxidation method with an average particle size of 11 nm. The heating characteristics of the magnetic nanoparticles were studied using infrared thermography and the effective specific absorption rate (ESAR) was compared with the literature. The ESAR obtained in our present studies for the nanoparticles of similar size dispersed in water are 20 × 10⁻⁹ and 36 × 10⁻⁹ Wg⁻¹Oe⁻² Hz⁻¹ for the uncoated and dextran coated magnetite respectively. The higher ESAR value for the dextran coated magnetite nanoparticles indicates that reduction in interparticle interaction influences the heating rate. The studies suggest that ESAR value could be used to determine the power dissipation contribution which follows the linear response theory. (paper)