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Previous issue date: 2011-02-24 === Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior === Hybrid systems formed from polymers and transition metals have now their physical and chemical properties extensively investigated for use in electronic devices. In this work,
Titanium Dioxide (TiO2) from the precursor of titanium tetrabutoxide and the composite system Poly(Ethylene Glycol)-Titanium Dioxide (TiO2-PEG) were synthesized by sol-gel
method. The PEG as acquired and TiO2 and composites powders were analyzed by X-Ray Diffraction (XRD), Spectroscopy in the Infrared region with Fourier transform (IRFT), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM)
and Electrochemical Impedance Spectroscopy (EIS). In the XRD analysis were observed in the TiO2 crystal faces of one of its polymorphs - anatase phase, crystal planes in Poly
(Ethylene Glycol) with considerable intensity and in the composite systems the mixture of crystal faces of their precursors isolated and reduction of crystallinity. The TG /
DTG suggested increasing the thermal instability of PEG in the composite powders as TiO2 is incorporated into the system. Spectral analysis presented in the infrared overlapping bands
for the polymer and metal oxide, reducing the intensity of symmetric stretching of ligand groups in the main chain polymer and angular deformations; were observed using SEM
micrographs of the morphological changes suffered by composite systems with the variation of the oxide concentration. Analyses by impedance spectroscopy indicated that the increased conductivity in composite occurs in line with the addition of the metal oxide concentration in the composite system === Sistemas h?bridos formados a partir de pol?meros e metais de transi??o atualmente t?m suas propriedades f?sicas e qu?micas extensivamente investigadas para aplica??o em dispositivos eletr?nicos. Neste trabalho, o Di?xido de Tit?nio (TiO2) a partir do precursor Tetrabut?xido de Tit?nio e o sistema comp?sito Poli (Etileno Glicol)-Di?xido de Tit?nio (PEG-TiO2) foram sintetizados pelo m?todo sol-gel. O PEG como adquirido e os p?s de TiO2
e comp?sitos obtidos foram analisados por Difra??o de Raios X (DRX), Espectroscopia de Absor??o na regi?o do Infravermelho com Transformada de Fourier (EIV-TF), An?lise Termogravim?trica (TG), Microscopia Eletr?nica de Varredura (MEV) e Espectroscopia de Imped?ncia Eletroqu?mica (EIE). Nas an?lises por DRX foram observadas no TiO2, faces
cristalinas de um de seus polimorfos fase anat?sio, planos cristalinos no PEG com intensidade substancial e nos sistemas comp?sitos a mistura de faces cristalinas dos seus
precursores na forma isolada, bem como, redu??o da cristalinidade. As curvas TG/DTG sugeriram o aumento da instabilidade t?rmica do PEG nos p?s comp?sitos ? medida que TiO2 ? incorporado ao sistema. A an?lise espectral na regi?o do infravermelho apresentou sobreposi??o de bandas relativas ao pol?mero e ao ?xido met?lico, redu??o da intensidade de
estiramentos sim?tricos dos grupos ligantes da cadeia principal polim?rica e deforma??es angulares; foram observadas atrav?s das micrografias de MEV modifica??es morfol?gicas sofridas pelos sistemas comp?sitos com a varia??o da concentra??o do ?xido. As an?lises por imped?ncia eletroqu?mica indicaram que o aumento da condutividade nos comp?sitos ocorre em conson?ncia com a adi??o da concentra??o do ?xido met?lico no sistema comp?sito
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