Correlation between the viscosity and the response to an alternating magnetic field of magnetite nanoparticles

M.L. MOJICA PISCIOTTI; R.D. ZYSLER; E. LIMA JR.; M. VASQUEZ MANSILLA

Paris

Conferencia; International Conference on Nanoscience + Technology (ICNT2012); 2012

ICNT

One of the most promising procedures involving diagnosis and treatment of cancer is the hyperthermia. This technique consists of making superparamagnetic nanoparticles (NPs) to be absorbed by cancer cells, thus when they interact with an AC magnetic field, the NPs receive energy from the field and then convert it into thermal energy. This leads to an aggressive increase of the temperature of cancer cells causing their death. One of the basic objectives to guarantee the effectiveness of hyperthermia is focused on the development of magnetic nanoparticles which surface can be modified to ensure their uptake by the tumor cells. Likewise, some specific environmental conditions must be analyzed too. This is the case of the microviscosity of the local environment.For this purpose, in this work we have studied the correlation between the heating response of magnetite (Fe3O4) NPs of different sizes and viscosity of the liquid in which they are suspend. We have synthetized the NPs through the method of high temperature decomposition of Fe(acac)3 and we studied their morphological and magnetic properties, checking that the synthesis method offers an optimal control over size and dispersion. Later on we coated the NPs with different surfactants and suspended them in aqueous media in order to measure the specific absortion rate (SAR). We found a strong dependence between the viscosity of the NPs in the solvent and their heating response. This clearly shows the importance of the surrounding medium for the maximization of heat dissipation.