Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-02-17T21:52:01Z No. of bitstreams: 1 CassiaMiriamLucasDaSilva_TESE.pdf: 6369550 bytes, checksum: 878790541a80c8aa8b58145a248dfec9 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-02-17T23:40:26Z (GMT) No. of bitstreams: 1 CassiaMiriamLucasDaSilva_TESE.pdf: 6369550 bytes, checksum: 878790541a80c8aa8b58145a248dfec9 (MD5) / Made available in DSpace on 2016-02-17T23:40:26Z (GMT). No. of bitstreams: 1 CassiaMiriamLucasDaSilva_TESE.pdf: 6369550 bytes, checksum: 878790541a80c8aa8b58145a248dfec9 (MD5) Previous issue date: 2014-02-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / A associa??o entre pol?meros e sais i?nicos, por intera??o f?sica, ? uma forma eficiente de prepara??o de filmes com interessantes propriedades mec?nica e el?trica. Embora a combina??o f?sica entre os pol?meros e os sais e a obten??o de filme autossustent?vel pelo m?todo de evapora??o possa ser facilmente conseguida, as propriedades desse novo composto pode ser bem diferentes dos componentes separados. Este trabalho descreve as novas propriedades el?tricas do comp?sito alginato de s?dio/poli(etileno glicol)/glicerol sem e com modifica??o com os sais de tungstato de s?dio e tetrabut?xido de tit?nio atrav?s de intera??es f?sicas entres eles. A prepara??o do filme se deu pelo m?todo sol-gel, tanto da matriz polim?rica pura (alginato de s?dio/poli(etileno glicol)/glicerol) como da matriz polim?rica dopada com diferentes al?quotas, 1, 2, 3 e 4 mL, da solu??o de tungstato de s?dio na concentra??o de 1mmol/L e, 0,1, 0,2, 0,3 e 0,4 mL de tetrabut?xido de tit?nio, adicionadas diretamente na matriz; em uma amostra da mistura polim?rica, tamb?m foi estudada a mistura das maiores concentra??es dos dois sais associados. Os filmes foram caracterizados atrav?s da reflex?o total atenuada (ATR), difratometria de raios X (DRX), microscopia eletr?nica de varredura (MEV), espectroscopia de raios X por dispers?o de energia (EDS) e as contribui??es dos sais nas propriedades el?tricas dos filmes foram analisadas atrav?s da espectroscopia de imped?ncia eletroqu?mica (EIE). O filme de alginato de s?dio com o poli(etileno glicol) apresenta rigidez mec?nica dificultando a trabalhabilidade do filme, entretanto, a adi??o do glicerol reduz as for?as intermoleculares entre as cadeias polim?ricas diminuindo essa fragilidade devido ao pequeno tamanho da cadeia, permitindo que seja inserido com mais facilidade entre as cadeias polim?ricas e, consequentemente, exer?a maior influ?ncia sobre as propriedades mec?nicas do que a maior mol?cula do poli(etileno glicol). As intera??es f?sicas s?o comprovadas atrav?s dos espectros de ATR. As bandas caracter?sticas do alginato n?o s?o deslocadas e ocorre aumento da ?rea das bandas e favorecimento de vibra??es na presen?a do glicerol. Os difratogramas evidenciaram a predomin?ncia do comportamento amorfo nos filmes. As an?lises de MEV mostraram a predomin?ncia de uma superf?cie mais lisa quando o glicerol est? presente nos filme e, na presen?a dos sais, as micrografias apresentam a exist?ncia de poros e irregularidade superficiais, assim como, heterogeneidade. Quando os sais est?o associados no mesmo filme h? a predomin?ncia de distribui??o de microestruturas. Atrav?s da EIE observou-se que a associa??o do glicerol e PEG no filme de NaAlg produz um comportamento caracter?stico de transporte de carga com uma condutividade na ordem de 10-4 ??1 .cm -1. Quando o comp?sito est? associado com o tungstato de s?dio apresenta um comportamento de armazenamento de carga e, quando a associa??o ? com o tetrabut?xido de tit?nio o transporte de carga ? favorecido, sendo esse comportamento observado tamb?m no filme com a mistura dos sais, gerando valor de condutividade na ordem de 10-3 ??1 .cm -1. A associa??o dos sais na matriz polim?rica aumenta a mobilidade i?nica extr?nseca do comp?sito e melhora suas propriedades condutoras. / The association between polymers and ionic salts by physical interaction, is an efficient way of making films with interesting mechanical and electrical properties. Although physical combination of polymers and salts and the obtaining of self-sustaining film by evaporation method can be easily achieved, the properties of this new compound may be different from the separate components. This work describes the electrical properties of new composite sodium alginate/poly(ethylene glycol)/glycerol with and without modification with the salts of sodium tungstate and titanium tetrabutoxide through physical interactions among them. The preparation of the film made by the sol-gel method, both the pure polymer matrix (sodium alginate/poly (ethylene glycol)/glycerol) and the polymeric matrix doped with varying rates 1, 2, 3 and 4 mL solution of sodium tungstate at a concentration of 1 mmol/L, and 0,1, 0,2, 0,3, and 0,4 ml of titanium tetrabutoxide in a sample of the polymer mixture, was studied the mixture of higher concentrations of the two salts associated. The films were characterized by attenuated total reflection (ATR), X-ray diffraction (XRD), scanning electron microscopy (SEM), X-Ray Spectroscopy Energy Dispersive (EDS) and the contributions of salts on the electrical properties of the films were analyzed by electrochemical impedance spectroscopy (EIS). The film of sodium alginate with poly (ethylene glycol) has mechanical rigidity making it difficult the workability of the film, however, the addition of glycerol reduces the intermolecular forces between the polymer chains reducing such fragility due to the small size of the chain, allowing it to be inserted more easily in the polymer chain, and thus exert greater influence on the mechanical properties of the poly(ethylene glycol) larger molecule. Physical interactions are proven through the ATR spectra. The characteristics bands of alginate are not displaced, increasing the area of the bands and favors of vibrations in the presence of glycerol occurs. The XRD patterns showed the predominance of the behavior amorphous in films. SEM analyzes showed the predominance of a smoother surface when glycerol is present in the film, and when the salts are associated micrographs show the existence of pores and surface irregularities, as well as heterogeneity. When salts are associated in the same film there is a predominant distribution of microstructures. Through the EIS it was observed that the association of glycerol and PEG in NaAlg film produces a characteristic behavior of charge transport with a conductivity on the order of 10-4 ?-1 .cm -1. When the composite is associated with sodium tungstate presents a charge storage behavior, and when the association is with the titanium tetrabutoxide charge transport is favored, and in the film with the mixture of the salts the conductivity value is in the order 10-3 ? -1 .cm -1. The association of salts increases the extrinsic ionic mobility of the composite and improvement in their conductive properties.