Efeito da dopagem de zinco e níquel nas propriedades fotocatalíticas e antimicrobiana da hidroxiapatita
Nanostructured hydroxyapatite (HAp) has been studied in advanced technologies in the catalytic area and in the field of biomedicine, such as drugs and protein transporters. In this work, HAp nanoparticles were synthesized by microwave-assisted hydrothermal method and doped with different concentr...
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| Formato: | Dissertação |
| Idioma: | pt_BR |
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Universidade Federal do Rio Grande do Norte
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| Endereço do item: | https://repositorio.ufrn.br/handle/123456789/57492 |
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| Resumo: | Nanostructured hydroxyapatite (HAp) has been studied in advanced technologies in
the catalytic area and in the field of biomedicine, such as drugs and protein
transporters. In this work, HAp nanoparticles were synthesized by microwave-assisted
hydrothermal method and doped with different concentrations of zinc and nickel ions.
The samples were characterized by the X-ray diffraction technique (XRD), Fourier
transform infrared spectroscopy (FTIR) and by field emission scanning electron
microscopy (FEM-FEG), respectively. Optical properties were estimated in the UV-Vis
region to calculate the gap energy value. The hydrothermal method used in this work
proved to be efficient for obtaining HAp nanoparticles. The XRD patterns together with
the structural refinement, showed the HAp formation for all samples, which
corresponds to the hexagonal crystalline structure. There was no secondary phase
formation, indicating that doping was successful. The FTIR spectra indicated that Zn2+
and Ni2+ doping in the HAp network did not change the vibrational modes of the main
HAp functional groups. The SEM-FEG micrographs illustrated an agglomeration of the
particles with the increase in the percentage of dopant ions in the structure, presenting
nanorod formats. The gap energy of HAp doped and co-doped with zinc and nickel
varied between 5.75 eV and 3.26 eV. The photocatalytic properties through the
degradation of methylene blue dye (MB) under UV and solar irradiation were
investigated, as well as the antimicrobial activity against gram positive
(Staphylococcus aureus) and gram negative (Escherichia coli) bacteria. The results of
the photocatalytic activity indicated 66.81% degradation of the MB dye under UV
irradiation for the H5Z sample and 97.85% degradation when subjected to solar
irradiation. To analyze the reuse applicability of the photometers, the samples were
submitted to three cycles of reuse. The H5Z sample showed 55% efficiency after reuse
cycles. The antimicrobial activity results showed that the H5Z, H5Z5N, H10Z5N and
H15Z5N samples showed an inhibition zone of 18.5; 14.5; 18 and 17mm, respectively,
against Gram negative bacteria (Escherichia coli), indicating the antibacterial effect of
samples with higher percentages of zinc in the synthesized HAp structure. Thesamples
did not show antimicrobial action against S.aureus bacteria. |
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