Nanopartículas magnéticas obtidas por coprecipitação homogênea sonoquimicamente assistida

Abstract

This work aims at obtaining nanoparticles of magnetic iron oxides with small size distribution in order to be applied in diverse fields of biomedicine such as, drug carriers, hyperthermia, diagnosis, among others. The magnetic nanoparticles syntheses were done in aqueous medium containing urea, which by heating has decomposed promoting the homogeneous coprecipitation. The urea thermal decomposition was assisted by high energy ultrasound. The precursor salts used were iron ferrous sulfate and ferrous chloride. The effect of cavitation generated by ultrasound changes the reaction environment, allowing formations of different phases from those related in literature. It was observed that the greater the amplitude of the energy delivered by the ultrasound earlier initiated the process of nucleation and particle formed will have smaller sizes. All samples presented magnetic behavior when in presence of a permanent magnet, even in samples with secondary phases according to X-ray powder diffractions results. Magnetic nanoparticles were obtained at pH lower than 6, different of ordinary findings in literature.