Universidade Federal do Piauí

Evento: 137º Defesa de Dissertação do Mestrado em Química

Local: Auditório do Departamento de Química

Data: 31/05/2013

 

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa. 
DATA: 31/05/2013
LOCAL: Auditório do Departamento de Química

Resumo

Nanocomposites containing Fe3O4 nanoparticles and Tannic Acid (TA) were synthesized by co precipitation method and were characterized by Transmission Electron Microscopy (TEM), Fourier Transformer Infrared Spectroscopy (FTIR), Zeta Potential, and X-Ray Diffraction. TEM images show that, in the nanocomposites produced, (Fe3O4) NPs suffer interference of Tannic Acid during their nucleation process. The samples showed that addition of TA do Fe3O4 make them more soluble in aqueous media. XRD analyses point that TA-Fe3O4 presents a better crystalline profile when compared to the other nanocomposite produced, Fe3O4-TA, in which, the interference of Tannic Acid in the crystalinity of nanoparticles is more pronounced. FTIR shows, to Fe3O4, a typical band at 575 cm-1 mode of the Fe-O bond in NPs, which shifts to shorter wavenumbers, 565 cm-1 and 570 cm-1 , respectively, to TA- Fe3O4, and Fe3O4-TA. Zeta potential measurements indicates that pure Fe3O4 NPS are stable because presents a value larger than – 30mV, and also points that addition of TA increases these values and prevents the agglomeration of nanoparticles. Also, cyclic voltammetry for AT-Fe3O4 nanocomposite exhibited one redox pair at -0.20 V and two irreversible processes (+0.24 and +0.29 V) attributed to Fe2+/Fe3+ and conversion of fenolic to quinone species.

Presidente - WELTER CANTANHÊDE DA SILVA

Interno - GERALDO EDUARDO DA LUZ JÚNIOR

Externo à Instituição - JACKSON DIRCEU MEGIATTO JÚNIOR - UNICAMP