Detalhes bibliográficos
| Ano de defesa: |
2012 |
| Autor(a) principal: |
Lima, Francisco António Paquete
 |
| Orientador(a): |
Papaléo, Ricardo Meurer
|
| Banca de defesa: |
Não Informado pela instituição |
| Tipo de documento: |
Dissertação
|
| Tipo de acesso: |
Acesso aberto |
| Idioma: |
por |
| Instituição de defesa: |
Pontifícia Universidade Católica do Rio Grande do Sul
|
| Programa de Pós-Graduação: |
Programa de Pós-Graduação em Engenharia e Tecnologia de Materiais
|
| Departamento: |
Faculdade de Engenharia
|
| País: |
BR
|
| Palavras-chave em Português: |
|
| Área do conhecimento CNPq: |
|
| Link de acesso: |
http://tede2.pucrs.br/tede2/handle/tede/3217
|
Resumo: |
In this study we investigated the synthesis and characterization (morphological structural and magnetic) of iron oxide nanoparticles coated with dextran and functionalized with amino groups, which are useful as contrast agents for magnetic resonance imaging. For the synthesis we used the method of co-precipitation of Fe (III) and Fe (II) with ammonium hydroxide. Three batches of samples were synthesized under identical conditions. The analysis of samples from each batch revealed some differences in the stability against agglomeration and iron concentrations (ranging from 10 to 8 mg / mL). A narrow size distribution of the nanoparticles was observed by DLS (Dynamic Light Scattering) in all cases with a mean hydrodynamic diameter of about 10 nm. The mean particle size was confirmed by TEM (Transmission Electron Microscopy), images. Elemental analysis by Rutherford Backscattering Spectrometry (RBS) and Energy Dispersive Spectroscopy (EDS) revealed a structure compatible with iron oxide, and a thermal decomposition pattern dominated by the polymer coating of the particles. The magnetic properties of the particles were confirmed by Alternating Gradient Force Magnetometer (AGFM) whit reveals a vanishing hysteresis loop. Measurements of the magnetic nuclear relaxivity were performed directly in a magnetic resonance imaging (MRI) equipment Whit an MRI phantom containing samples with different concentrations of the FeNP. The study of magnetic relaxation with test objects indicated a clear effect of the FeNP or the MRI signal through the decreases and T1 and T2 in aqueous solutions. Measured relaxivities obtaining from the curves of the relaxation rate versus FeNP concentration were between 41 and 24 mM-1s-1 for r2 and 2,0 to 1,7 mM-1s-1 for r1. We conclude that the method applied in the synthesis of the FeNP was be very efficient in producing NPs with suitable properties for use as a contrast agent in MRI images |
