A study of adsorption equilibria of oxygen, nitrogen and oxygen-nitrogen mixtures on types 4A, 5A, 13X and Na-Mordenite molecular sieve pellets has been made. Pure component isotherms, using a volumetric apparatus, have been measured for each gas on each adsorbent at pressures up to 9 bar and for temperatures of 278.15,293.15 and 303.15 K. Curve fitting of the pure canponent isotherms has been attempted using the kinetic model of Gonzalez and Holland, the vacancy solution model, the statistical thermodynamic model and a mathematical equation similar to the Hill-de Boer model. With the exception of the kinetic model, good curve fitting was obtained. Binary equilibria data have been measured, using a constant volume method, for mixtures of oxygen and nitrogen at pressures of 1.7 and 4.4 bar and at temperatures of 278.15,293.15 and 303.15 K for each of the adsorbents. These results have been presented graphically as equilibrium phase compositions and corresponding total adsorption loadings. The binary experimental equilibria data have been examined against values predicted by mixture models (kinetic model, the extended vacancy solution model, the statistical thermodynamic model, the Cook and Basmadjian model, and the ideal adsorbed solution theory) using regression parameters obtained from the pure component isotherms. The statistical thermodynamic model and the ideal adsorbed solution theory gave the best representation of the experimental data. The activity coefficients of the adsorbed phase for the binary experimental data have been calculated and the results showed no appreciable deviation of the adsorbed phase from ideality. / British Council and the University of Gezira (Sudan)

A study of adsorption equilibria of oxygen, nitrogen and oxygen-nitrogen mixtures on types 4A, 5A, 13X and Na-Mordenite molecular sieve pellets has been made. Pure component isotherms, using a volumetric apparatus, have been measured for each gas on each adsorbent at pressures up to 9 bar and for temperatures of 278.15,293.15 and 303.15 K. Curve fitting of the pure canponent isotherms has been attempted using the kinetic model of Gonzalez and Holland, the vacancy solution model, the statistical thermodynamic model and a mathematical equation similar to the Hill-de Boer model. With the exception of the kinetic model, good curve fitting was obtained. Binary equilibria data have been measured, using a constant volume method, for mixtures of oxygen and nitrogen at pressures of 1.7 and 4.4 bar and at temperatures of 278.15,293.15 and 303.15 K for each of the adsorbents. These results have been presented graphically as equilibrium phase compositions and corresponding total adsorption loadings. The binary experimental equilibria data have been examined against values predicted by mixture models (kinetic model, the extended vacancy solution model, the statistical thermodynamic model, the Cook and Basmadjian model, and the ideal adsorbed solution theory) using regression parameters obtained from the pure component isotherms. The statistical thermodynamic model and the ideal adsorbed solution theory gave the best representation of the experimental data. The activity coefficients of the adsorbed phase for the binary experimental data have been calculated and the results showed no appreciable deviation of the adsorbed phase from ideality.

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Es werden die Gleichgewichtskonstanten der Zinkextraktion ermittelt. Das Wilson-Modell und das erweiterte Debye-Hückel-Gesetz werden zur Beschreibung der Aktivitäten verwendet. Die tensiometrischen Untersuchungen erfolgen am hängenden Tropfen. Die Modellauswahl zur Beschreibung der Gleichgewichtsgrenzflächenspannung erfolgt im submizellaren Konzentrationsbereich. Die pseudo-nichtionische Modellierung auf der Basis der Langmuir-Isothermen der Mehrkomponentenadsorption bei Verwendung der Stern-Isothermen für die Gegenionenanreicherung liefert die beste Datenanpassung. Durch ein einfaches Modell zur Mizell- und Aggregatbildung gelingt die Modellerweiterung. Die gemessenen dynamischen Grenzflächenspannungskurven werden sorptionskinetisch und durch diffusive Approximationen angepasst. Es zeigt sich, dass der Stofftransport diffusionsdirigiert ist. Am oszillierenden Tropfen werden die Ergebnisse bestätigt. Für das Kationenaustauscheranion wird die Gültigkeit des Maxwell-Modells zur Beschreibung der Grenzflächendilatationsrheologie nachgewiesen.

Orientador: Yoshitaka Gushikem / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-12T16:49:45Z (GMT). No. of bitstreams: 1 Magosso_HericaAparecida_D.pdf: 835979 bytes, checksum: 2898b43a1168c04ffdef965b55b067fa (MD5) Previous issue date: 2008 / Resumo: Este trabalho reporta a preparação, caracterização e aplicação de novos polímeros íon-trocadores denominados cloreto de 3-n-propil (3-metilpiridínio) silsesquioxano e cloreto de 3-n-propil (4-metilpiridínio) silsesquioxano, obtidos a partir da incorporação de quantidades variáveis de grupos metilpiridínio aos materiais. Os polímeros obtidos se mostraram insolúveis nos solventes mais comuns, inclusive água, o que representou uma vantagem, já que permitiu sua utilização na forma em que foram preparados, sem a necessidade de suportá-los sobre nenhum substrato sólido para serem utilizados. Os espectros de RMN C e infravermelho mostraram que as sínteses foram bem sucedidas. Os resultados de análise termogravimétrica mostraram que os materiais estudados são termicamente estáveis até valores próximos a 500 K, o que representa uma característica interessante dos materiais, já que o processo de regeneração dos mesmos envolve secagem a 373 K sob vácuo. Os polímeros obtidos a partir da incorporação do grupo funcional 3-metilpiridínio, denominados Si3-PicCl-A e Si3-PicCl-B, os quais se diferem somente pela quantidade de grupo funcionais fixados, apresentaram capacidades de troca iônica iguais a 1,91 e 0,90 mmol L, respectivamente, enquanto aqueles obtidos pela incorporação do grupo funcional 4-metilpiridínio, denominados Si4-PicCl-A e Si4-PicCl-B, apresentaram capacidades de troca iônica iguais a 1,46 e 0,81 mmol L, respectivamente. Os polímeros Si3-PicCl-B e Si4-PicCl-B foram usados no processo de adsorção de íons cobre e zinco de solução etanólica e o polímero Si4-PicCl-A foi usado na adsorção de íons mercúrio, cádmio e zinco de solução aquosa. A metodologia de cálculo utilizada para se obter os parâmetros de ajuste das isotermas de adsorção foi baseada no modelo dos centros bidentados fixos. Os resultados de adsorção obtidos mostraram a viabilidade do uso dos polímeros como eficientes materiais adsorventes. O último polímero reportado neste trabalho, denominado Si3-PicCl-A, foi aplicado no desenvolvimento de um sensor amperométrico altamente sensível a nitrito. Os resultados obtidos mostraram a viabilidade da aplicação do material no desenvolvimento de um novo sensor para a aplicação proposta / Abstract: This work reports the preparation, characterization and applications of the new ion-exchanger polymers named 3-n-propyl(3-methylpyridinium) silsesquioxane chloride and 3-n-propyl(4-methyl pyridinium) silsesquioxane chloride prepared by the fixation of different amounts of methylpyridinium groups into the materials. The obtained materials were insoluble in the most common solvents, including water. This property was considered as an advantage since it allowed their use as prepared, without the necessity to be supported on the solid substract surface before using. The C NMR and infrared spectra showed that the syntheses were successfully. Thermogravimetric analysis showed that the obtained materials are thermally very stable up to 500 K, an important characteristic since their regeneration process, after using, includes drying the solid at temperature of 373 K under low pressure. The two obtained materials having as functional group the 3-methylpyridinium ion, named Si3-PicCl-A and Si3-PicCl-B, which differ each other just by the amount of functional groups immobilized, presented ion exchanger capacity equal to 1.91 e 0.90 mmol L, respectively, and those obtained having as functional group the 4-methylpyridinium ion, named Si4-PicCl-A and Si4-PicCl-B, presented ion exchanger capacity equal to 1.46 e 0.81 mmol L, respectively. The materials Si3-PicCl-B and Si4-PicCl-B were used in the adsorption process of copper and zinc ions from ethanol solution and the polymer Si4-PicCl-A was used in the adsorption process of mercury, cadmium and zinc ions from aqueous solution. The calculation methodology used to obtain the fit parameters of the adsorption isotherms was based on the model of fixed bidentate centers. The obtained adsorption results showed the viability of using the polymers as efficient adsorvent materials. The last polymer reported in this work, named Si3-PicCl-A, was applied in the development of a highly sensitive amperometric sensor for nitrite. The obtained results showed the viability of the application of the material in the development of a new sensor for the proposed application / Doutorado / Quimica Inorganica / Doutor em Ciências

Es werden die Gleichgewichtskonstanten der Zinkextraktion ermittelt. Das Wilson-Modell und das erweiterte Debye-Hückel-Gesetz werden zur Beschreibung der Aktivitäten verwendet. Die tensiometrischen Untersuchungen erfolgen am hängenden Tropfen. Die Modellauswahl zur Beschreibung der Gleichgewichtsgrenzflächenspannung erfolgt im submizellaren Konzentrationsbereich. Die pseudo-nichtionische Modellierung auf der Basis der Langmuir-Isothermen der Mehrkomponentenadsorption bei Verwendung der Stern-Isothermen für die Gegenionenanreicherung liefert die beste Datenanpassung. Durch ein einfaches Modell zur Mizell- und Aggregatbildung gelingt die Modellerweiterung. Die gemessenen dynamischen Grenzflächenspannungskurven werden sorptionskinetisch und durch diffusive Approximationen angepasst. Es zeigt sich, dass der Stofftransport diffusionsdirigiert ist. Am oszillierenden Tropfen werden die Ergebnisse bestätigt. Für das Kationenaustauscheranion wird die Gültigkeit des Maxwell-Modells zur Beschreibung der Grenzflächendilatationsrheologie nachgewiesen.