Novos materiais híbridos à base de ZnAl2O4 dopados com európio.

Abstract

Nanoparticles ZnAl1,9Eu0,1O4 were surface modified using amino-silane agents, and from functionalized monomers like methylmethacrylate, ethylenediamine and chitosan as biocompatible molecules. Nanoparticles of ZnAl1,9Eu0,1O4 were obtained by combustion reaction, and silanized with silane agents and 3- aminopropyltrimethoxysilane and 3 -aminopropyltriethoxysilane, in order to make the hydrophobic character of the spinel and then functionalized. The resulting samples were characterized by X-ray Diffraction, Infrared Spectroscopy Fourier Transform, Transmission Electron Microscopy, Excitation and Emission Spectroscopy and quantum yield. The results revealed the formation of cubic phase ZnAl1,9Eu0,1O4 and traces of EuAlO3. For samples functionalized with chitosan, we observed the formation of spinel phase and phase chitosan. Through the FTIR spectra observed bands below 1000 cm-1 assigned to the vibrations of tetrahedral and octahedral sites. The samples functionalized with chitosan showed better complexation (interaction oxide / polymer) and the presence of NH stretch assigned to NH2 group of chitosan. C = O band observed for the spinel ZnAl1,9Eu0,1O4 with chitosan showed the functionalization of nanoparticles. Nanoparticles ZnAl1,9Eu0,1O4 showed morphology composed of needle-shaped clusters consisting of particles with roughly hexagonal shape, and size smaller than 100 nm. Nanoparticles ZnAl1,9Eu0,1O4 after functionalization showed inhomogeneous morphology, consisting of a film and impregnated particles of roughly spherical shape containing amorphous and crystalline phases, with particles smaller than 100 nm. The silanized samples, functionalized with monomers functionalized with chitosan and the sample in 5:1 ratio showed the spectral lines corresponding Eu3+ ion transitions 5D0 → 7F0, 7F1 → 5D0, 5D0 → 7F2, 5D0 → 7F3 and 5D0 → 7F4. The higher quantum yield observed for the sample was functionalized with a mixture of monomers using the 3-aminopropyltrimethoxysilane.