Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-03-23T18:44:54Z No. of bitstreams: 1 JANAINA RAFAELLA SCHEIBLER - DISSERTAÇÃO PPGEQ 2015..pdf: 2465420 bytes, checksum: cbecc726b67d3d76a334570b655735eb (MD5) / Made available in DSpace on 2018-03-23T18:44:54Z (GMT). No. of bitstreams: 1 JANAINA RAFAELLA SCHEIBLER - DISSERTAÇÃO PPGEQ 2015..pdf: 2465420 bytes, checksum: cbecc726b67d3d76a334570b655735eb (MD5) Previous issue date: 2015 / Entre as membranas inorgânicas microporosas, as membranas zeolíticas constituem uma tecnologia promissora, devido às suas potenciais aplicações normalmente na desidratação do álcool, separação de moléculas de gás, separação de isômeros ou em processos químicos, incluindo reações de esterificação. Sob este aspecto, torna-se imprescindível o estudo das rotas de preparação desses materiais, visando desenvolver produtos com qualidade e a baixo custo. Portanto, a inovação deste estudo se dá na síntese de membranas zeolíticas via método de síntese poreplugging visando a utilização das membranas inorgânicas para permeação gasosa de N2. Neste trabalho foram desenvolvidos os seguintes materiais: zeólita ZSM-5, membranas cerâmicas (γ-alumina e α-alumina) e as membranas zeolíticas (ZSM5/γ-alumina e ZSM-5/α-alumina). A zeólita ZSM-5 foi sintetizada por meio do método hidrotérmico. As membranas cerâmicas (γ-alumina e α-alumina) foram preparadas a partir da técnica de conformação de pós cerâmicos e posteriormente submetidas à sinterização a uma temperatura de 1000 ºC/1h e 1200 ºC/1h respectivamente. A preparação das membranas zeolíticas (ZSM-5/γ-alumina e ZSM-5/α-alumina) foi realizada com base no método pore in plugging. As amostras foram caracterizadas a partir das técnicas de difração de raios X e Microscopia Eletrônica de Varredura. Os resultados experimentais permitem diversas conclusões acerca do desenvolvimento dos materiais: zeólita ZSM-5, membranas cerâmicas (γ-alumina e α-alumina) e membranas zeolíticas (ZSM-5/γ-alumina e ZSM-5/α-alumina). A partir da difração de raios X, foi possível verificar que o método de síntese empregado, foi efetivo na obtenção da zeólita ZSM-5. O difratograma apresentou picos característicos de uma zeólita ZSM-5 quando comparada ao padrão. Os resultados obtidos por DRX para as membranas cerâmicas (γ-alumina e α-alumina) demonstraram a formação de picos característicos do óxido de alumínio, os materiais são cristalinos e puros. Para o método pore-plugging pode se dizer que é um método promissor, pois mostrou uma formação satisfatória da camada zeolítica no resultado do DRX de ambas as membranas zeolíticas (ZSM-5/γ-alumina e ZSM-5/α-alumina). / Among the microporous inorganic membranes, zeolite membranes are a promising technology due to their potential applications normally in alcohol dehydration, separation of gas molecules, separation of isomers or chemical processes, including esterification reactions. In this regard, it is essential to study the preparation of these materials routes in order to develop products with quality and low cost. Therefore, innovation of this study gives the synthesis of zeolite membranes via pore-plugging synthesis method aimed at the use of inorganic membranes for gas permeation N2. In this work the following materials were developed: ZSM-5 zeolite, ceramic membranes (γ-alumina and α-alumina) and zeolitic membranes (ZSM-5/γ-alumina and ZSM-5/α-alumina). Zeolite ZSM-5 was synthesized by the hydrothermal method. Ceramic membranes (γ-alumina and α-alumina) were prepared from the ceramic powder forming technique, and subsequently subjected to a sintering temperature of 1000 °C/1h and 1200 °C/1h respectively. The preparation of zeolite membranes (ZSM-5/γ-alumina and ZSM-5/α-alumina) was carried out based on the method in pore plugging. The samples were characterized from the techniques of X diffraction and scanning electron microscopy rays. The experimental results allow several conclusions about the development of materials: zeolite ZSM-5, ceramic membranes (γ-alumina and α-alumina) and zeolite membranes (ZSM-5/γ-alumina and ZSM-5/αalumina). From the X-ray diffraction, it found that the method of synthesis used was effective in obtaining the zeolite ZSM-5. The XRD pattern showed peaks characteristic of ZSM-5 compared to the standard. The results obtained by XRD ceramic membranes (γ-alumina and α-alumina) showed the formation of peaks characteristic of aluminum oxide, the materials are crystalline and pure. For the poreplugging method can be said to be a promising method because it showed a satisfactory formation of the zeolite layer on the result of XRD both zeolite membranes (ZSM-5/γ-alumina and ZSM-5/α-alumina).

La synthèse d'acide polyamique (APA) comportant des blocs élastomères de type oligo-oxyéthylène et -oxypropylène et des polyimides correspondants (PEI) a été étudiée et leurs propriétés de perméation gazeuse déterminées pour He, N2, O2, H2, CH4 et CO2. Il a été montré que la présence de la phase élastomère augmentait de façon très importante les coefficients de perméabilité au gaz comparativement aux polyimides aromatiques conventionnels. La perméabilité du CO2, augmentée de façon préférentielle par rapport celles de tous les autres gaz, conduit à des sélectivités idéales tout à fait remarquables, en particulier vis-à-vis de N2 (≈40). L’incorporation de nanoparticules de silice dans les PEI (de 1 à 15% en masse) a été effectuée lors de l’étape de cyclo-déshydratation de l'APA, soit par ajout de silice hydrophobes (16 nm) ou hydrophiles (12 nm), soit par méthode Sol-Gel à partir de précurseurs alcoxysilanes (TMOS et TEOS). L'influence des charges SiO2 sur les propriétés de perméation gazeuse a été étudiée par la méthode du temps de retard (time-lag) essentiellement sur la série préparée avec des particules préformées. On a observé que les nano-charges de silice ne semblent pas interférer dans le processus de cyclisation et que les propriétés mécaniques sont renforcées ; la perméabilité aux gaz varie surtout selon la quantité de charges incorporées mais aucune augmentation spectaculaire de perméabilité n’a pu être observée. On peut en déduire que, vraisemblablement, c’est la phase élastomère qui est le lieu d’incorporation des particules de SiO2. Ces résultats montrent l’intérêt des membranes PEI et PEI/SiO2 dans des applications industrielles de séparation de gaz, notamment pour la séparation de mélanges CO2/N2 / The synthesis of polyamic acids (PAA) with oligo-oxyethylene and -oxypropylene rubbery blocks and the related polyimides (PEI) has been studied and their gas permeation properties determined for He, N2, O2, H2, CH4 and CO2. It was shown that the rubbery phase dramatically increased the gas permeability coefficients compared to conventional aromatic polyimides. The permeability of CO2 is preferentially increased in comparison to all other gases, leading to remarkable ideal selectivities, especially for the N2 mixture (≈40). The incorporation of silica nanoparticles in PEI (from 1 to 15 wt%) was carried out during the cyclo-dehydration of the PAA by adding fumed hydrophobic (16 nm) or hydrophilic (12 nm) silica, or by Sol-Gel approach using alkoxysilane precursors (TMOS and TEOS). The effect of SiO2-fillers on the properties of gas permeation has been studied by the time-lag method mainly on the series prepared with fumed silica. It was observed that nano-particles of silica do not seem to disturb the PAA cyclization process and that the mechanical properties are improved; the gas permeability varies essentially depending on the amount of fillers incorporated but no spectacular increase in permeability could be shown due to the nano-particles amounts. Apparently, it can be deduced that it is the rubbery phase which accommodates the SiO2 particles. These results showed the value of PEI and PEI/SiO2 membranes in industrial applications of gas separation, especially for the separation of CO2/N2 mixtures