Preparation of composite with silica-coated nanoparticles of iron oxide spinels for applications based on magnetically induced hyperthermia.

Submitted by giuliana silveira (giulianagphoto@gmail.com) on 2017-05-22T17:57:02Z No. of bitstreams: 1 ARTIGO_PreparationCompositeSilica.pdf: 599749 bytes, checksum: d63bd11321d35b3b2e571a582f802fe6 (MD5)Approved for entry into archive by Oliveira Flávia (flavia@sisbin.ufop.br) on 2017-05-23T16:47:27Z (GMT) No. of bitstreams: 1 ARTIGO_PreparationCompositeSilica.pdf: 599749 bytes, checksum: d63bd11321d35b3b2e571a582f802fe6 (MD5)Made available in DSpace on 2017-05-23T16:47:27Z (GMT). No. of bitstreams: 1 ARTIGO_PreparationCompositeSilica.pdf: 599749 bytes, checksum: d63bd11321d35b3b2e571a582f802fe6 (MD5) Previous issue date: 2013It is reported a novel method to prepare magnetic core (iron oxide spinels)–shell (silica) composites containing well-dispersed magnetic nanoparticles in aqueous solution. The synthetic process consists of two steps. In a first step, iron oxide nanoparticles obtained through co-precipitation are dispersed in an aqueous solution containing tetramethylammonium hydroxide; in a second step, particles of this sample are coated with silica, through hydrolyzation of tetraethyl orthosilicate. The intrinsic atomic structure and essential properties of the core–shell system were assessed with powder X-ray diffraction, Fourier transform infrared spectrometry, Mössbauer spectroscopy and transmission electron microscopy. The heat released by this ferrofluid under an AC-generated magnetic field was evaluated by following the temperature evolution under increasingmagnetic field strengths.Results strongly indicate that this ferrofluid based on silica-coated iron oxide spinels is technologically a very promising material to be used in medical practices, in oncology