Heating Effect in Biocompatible Magnetic Fluid

This work is devoted to the study of heating of a biocompatible magnetic fluid due to time-varying magnetic induction. The adsorption of dextran on magnetite particles was confirmed by IR spectroscopy. A considerable thickness of the surfactant layer (oleate sodium + dextran) of about 4.3 nm prevents the formation of clusters made of nanomagnetic particles as evidenced by the fact that no maxima of the ultrasound wave absorption coefficient corresponding to cluster formation have been detected. The results show that the observed heating effect may be applied in hyperthermia treatments especially in the preferable region of 500 – 800 kHz. An “H ²– law” observed for the dependence of the SAR on the square of the amplitude of the magnetic field demonstrates the presence of superparamagnetic particles in the ferrofluid. Paper presented at the Seventeenth European Conference on Thermophysical Properties, September 5-8, 2005, Bratislava, Slovak Republic.