Distillation and absorption columns offer significant energy demands for future development in the petrochemical and fine chemical industries. Membranes and adsorbents are attractive alternatives to these classical separation units due to lower operating cost and easy device fabrication; however, membranes possess an upper limit in separation performance that results in a trade-off between selectivity (purity) and permeability (productivity) for the target gas product, and adsorbents require the need to be water-resistant to natural gas streams in order to withstand typical gas compositions. Composite membranes, or mixed-matrix membranes, are an appealing alternative to pure polymeric membrane materials by use of a molecular sieve “filler” phase which has higher separation performance than the pure polymer. In this thesis, the structure-property-processing relationships for a new class of molecular sieves known as zeolitic imidazolate frameworks (ZIFs) are investigated for their use as the filler phase in composite membranes or as adsorbents. These materials show robust chemical and thermal stability and are a promising class of molecular sieves for acid gas (CO₂/CH₄) separations. The synthesis of mixed-linker ZIFs is first investigated. It is shown that the organic linker composition in these materials is controllable without changing the crystal structure or significantly altering the thermal decomposition properties. There are observable changes in the adsorption properties, determined by nitrogen physisorption, that depend on the overall linker composition. The results suggest the proposed synthesis route facilitates a tunable process to control either the adsorption or diffusion properties depending on the linker composition. The structure-property-processing relationship for a specific ZIF, ZIF-8, is then investigated to determine the proper processing conditions necessary for fabricating defect-free composite membranes. The effect of ultrasonication shows an unexpected coarsening of ZIF-8 nanoparticles that grow with increased sonication time, but the structural integrity is shown to be maintained after sonication by using X-ray diffraction, Pair Distribution Function analysis, and nitrogen physisorption. The permeation properties of composite membranes revealed that intense ultrasonication is necessary to fabricate defect-free membranes for CO₂/CH₄ gas separations. Finally, the separation properties of mixed-linker ZIFs is investigated by using adsorption studies of CO₂ and CH₄ and using composite membranes with differing linker compositions. Adsorption properties of mixed-linker ZIFs reveal that these materials possess tunable surface properties, and a selectivity enhancement of six fold over ZIF-8 is observed with mixed-linker ZIFs without changing the crystal structure. Gas permeation studies of composite membranes reveal that the separation properties of mixed-linker ZIFs are different from their parent frameworks. By proper selection of mixed-linker ZIFs, there is an overall improvement of separation properties in the composite membranes when compared to ZIF-8.

Regulações ambientais cada vez mais rigorosas em relação ao gerenciamento dos resíduos orgânicos estão impelindo a indústria para uma maior sustentabilidade no sentido de melhorar a relação beneficio/custo e também atender a demanda dos clientes. A valorização dos resíduos orgânicos é uma das áreas de investigação atuais que tem atraído grande atenção nos últimos anos como uma alternativa potencial à eliminação de uma vasta gama de resíduos em aterros sanitários. Os resíduos orgânicos como o lodo de esgoto têm sido encarados como um recurso com um potencial significativo para ser empregado como matéria-prima para a produção de vários tipos de produtos, materiais e combustíveis. Este estudo tem como objetivo fornecer subsídios sobre o potencial de uso de lodo de esgoto para produzir carvões ativados e novos materiais adsorventes misturando com diferentes materiais polissiloxanos para adsorção de poluentes orgânicos a partir de soluções aquosas. Os materiais adsorventes foram caracterizados por varias técnicas analíticas e funcionais e utilizados na adsorção de diclofenaco (DCF) , nimesulida (NM) e alguns compostos fenólicos a partir de soluções aquosas Esta tese visa contribuir em (i) comparar os métodos de pirólise (pirólise convencional e aquecimento assistido por micro-ondas) na preparação de carvões ativados a partir de lodo de esgoto. Para isso foi aplicado um planejamento experimental e metodologia de superfície de resposta no sentido de determinar quais as variáveis dos dois processos são as que influenciam na qualidade do carvão produzido; (ii) a combinação de lodo de esgoto com polissiloxanos para preparar adsorventes para adsorção de fármacos a partir de soluções aquosas por processos de adsorção. Os achados gerais desta tese mostraram (i) que ambos os métodos de pirólise produzem carvões ativados com elevadas porosidades e áreas superficiais; (ii) demonstrou-se também que lodo de esgoto pode ser um excelente precursor para a preparação de carvões ativados e que pode com sucesso ser combinado com outros precursores (como polissiloxanos) a fim de se obter novos materiais com diferentes funcionalidades e características; (iii) foi demonstrado que os carvões ativados, híbridos e materiais compósitos desenvolvidos durante o presente estudo são ótimos adsorventes, especialmente para a remoção de diclofenaco DCF e NM a partir de solução aquosa e; (iv) tanto por microondas ou por pirólise convencional, é possível desenvolver CAs de lodo de esgoto com alta eficiência para a remoção de compostos fenólicos em comparação com outros tipos de CAs relatados na literatura. Estes resultados indicam que o lodo de esgoto e polissiloxanos têm grande potencial como precursores para a preparação de materiais adsorventes para o tratamento de água poluída por compostos orgânicos. / Increasingly tighter regulations regarding organic waste are pushing the manufacturing industry toward higher sustainability to improve cost-effectiveness and meet customers’ demand. Organic waste valorisation is one of the current research areas that have attracted a great deal of attention over the past few years as a potential alternative to the disposal of a wide range of residues in landfill sites. Bio-waste like sewage sludge emerged as a resource with a significant potential to be employed as a raw material for the production of chemicals, materials and fuels given its abundant volumes generated globally. This study aims at providing insights into the potential of the use of the sewage sludge to produce activated carbons (ACs) and novel adsorbent materials mixing with different polysiloxanes materials for adsorption of organic pollutants from aqueous solutions. The characterization of adsorbents were achieved by several analytical and functional techniques and used for adsorption of diclofenac (DCF) and nimesulide (NM) from aqueous solutions. The novelties of the present study are (i) to compare both pyrolysis methods (conventional pyrolysis and microwave assisted heating) for preparation of activated carbons from sewage sludge for that It was applied an experimental design and response surface methodology were used for the preparation and comparison of activated carbon produced by both methods, conventional furnace and microwave; (ii) the combination of sewage sludge with polysiloxanes to prepare adsorbents to uptake pharmaceuticals and phenolic compounds from aqueous solutions by adsorption processes. The general findings of this thesis showed (i) that both methods of pyrolysis produce very good activated carbons from sewage sludge with high specific surface areas and high developed porosities; (ii) It was also shown that the sewage sludge can be an excellent precursor to prepare activated carbons and novels materials by mixing it with other precursors such polysiloxanes; (iii) It was shown that the activated carbons, hybrids and composites materials developed during the present study are good adsorbents, especially for the removal of a model diclofenac (DCF) and nimesulide (NM) from aqueous solution and; (iv) that by microwave and conventional pyrolysis it is possible to develop sludge-ACs with very high efficiency for phenolic compounds compared with others kind of ACs reported in literature. These results indicate that sewage sludge and polysiloxanes have great potential as precursors for preparation of adsorbent materials for water treatment polluted by organic pollutants compounds.

Made available in DSpace on 2014-10-09T12:44:25Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:07:22Z (GMT). No. of bitstreams: 1 06909.pdf: 4920910 bytes, checksum: d6e37e56c96b5266b7fcce3da3d56d3b (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Regulações ambientais cada vez mais rigorosas em relação ao gerenciamento dos resíduos orgânicos estão impelindo a indústria para uma maior sustentabilidade no sentido de melhorar a relação beneficio/custo e também atender a demanda dos clientes. A valorização dos resíduos orgânicos é uma das áreas de investigação atuais que tem atraído grande atenção nos últimos anos como uma alternativa potencial à eliminação de uma vasta gama de resíduos em aterros sanitários. Os resíduos orgânicos como o lodo de esgoto têm sido encarados como um recurso com um potencial significativo para ser empregado como matéria-prima para a produção de vários tipos de produtos, materiais e combustíveis. Este estudo tem como objetivo fornecer subsídios sobre o potencial de uso de lodo de esgoto para produzir carvões ativados e novos materiais adsorventes misturando com diferentes materiais polissiloxanos para adsorção de poluentes orgânicos a partir de soluções aquosas. Os materiais adsorventes foram caracterizados por varias técnicas analíticas e funcionais e utilizados na adsorção de diclofenaco (DCF) , nimesulida (NM) e alguns compostos fenólicos a partir de soluções aquosas Esta tese visa contribuir em (i) comparar os métodos de pirólise (pirólise convencional e aquecimento assistido por micro-ondas) na preparação de carvões ativados a partir de lodo de esgoto. Para isso foi aplicado um planejamento experimental e metodologia de superfície de resposta no sentido de determinar quais as variáveis dos dois processos são as que influenciam na qualidade do carvão produzido; (ii) a combinação de lodo de esgoto com polissiloxanos para preparar adsorventes para adsorção de fármacos a partir de soluções aquosas por processos de adsorção. Os achados gerais desta tese mostraram (i) que ambos os métodos de pirólise produzem carvões ativados com elevadas porosidades e áreas superficiais; (ii) demonstrou-se também que lodo de esgoto pode ser um excelente precursor para a preparação de carvões ativados e que pode com sucesso ser combinado com outros precursores (como polissiloxanos) a fim de se obter novos materiais com diferentes funcionalidades e características; (iii) foi demonstrado que os carvões ativados, híbridos e materiais compósitos desenvolvidos durante o presente estudo são ótimos adsorventes, especialmente para a remoção de diclofenaco DCF e NM a partir de solução aquosa e; (iv) tanto por microondas ou por pirólise convencional, é possível desenvolver CAs de lodo de esgoto com alta eficiência para a remoção de compostos fenólicos em comparação com outros tipos de CAs relatados na literatura. Estes resultados indicam que o lodo de esgoto e polissiloxanos têm grande potencial como precursores para a preparação de materiais adsorventes para o tratamento de água poluída por compostos orgânicos. / Increasingly tighter regulations regarding organic waste are pushing the manufacturing industry toward higher sustainability to improve cost-effectiveness and meet customers’ demand. Organic waste valorisation is one of the current research areas that have attracted a great deal of attention over the past few years as a potential alternative to the disposal of a wide range of residues in landfill sites. Bio-waste like sewage sludge emerged as a resource with a significant potential to be employed as a raw material for the production of chemicals, materials and fuels given its abundant volumes generated globally. This study aims at providing insights into the potential of the use of the sewage sludge to produce activated carbons (ACs) and novel adsorbent materials mixing with different polysiloxanes materials for adsorption of organic pollutants from aqueous solutions. The characterization of adsorbents were achieved by several analytical and functional techniques and used for adsorption of diclofenac (DCF) and nimesulide (NM) from aqueous solutions. The novelties of the present study are (i) to compare both pyrolysis methods (conventional pyrolysis and microwave assisted heating) for preparation of activated carbons from sewage sludge for that It was applied an experimental design and response surface methodology were used for the preparation and comparison of activated carbon produced by both methods, conventional furnace and microwave; (ii) the combination of sewage sludge with polysiloxanes to prepare adsorbents to uptake pharmaceuticals and phenolic compounds from aqueous solutions by adsorption processes. The general findings of this thesis showed (i) that both methods of pyrolysis produce very good activated carbons from sewage sludge with high specific surface areas and high developed porosities; (ii) It was also shown that the sewage sludge can be an excellent precursor to prepare activated carbons and novels materials by mixing it with other precursors such polysiloxanes; (iii) It was shown that the activated carbons, hybrids and composites materials developed during the present study are good adsorbents, especially for the removal of a model diclofenac (DCF) and nimesulide (NM) from aqueous solution and; (iv) that by microwave and conventional pyrolysis it is possible to develop sludge-ACs with very high efficiency for phenolic compounds compared with others kind of ACs reported in literature. These results indicate that sewage sludge and polysiloxanes have great potential as precursors for preparation of adsorbent materials for water treatment polluted by organic pollutants compounds.

Made available in DSpace on 2014-10-09T12:44:25Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:07:22Z (GMT). No. of bitstreams: 1 06909.pdf: 4920910 bytes, checksum: d6e37e56c96b5266b7fcce3da3d56d3b (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Submitted by Erika Demachki (erikademachki@gmail.com) on 2015-11-12T17:47:20Z No. of bitstreams: 2 Dissertação - Lícia Aparecida da Silva - 2015.pdf: 2121079 bytes, checksum: b400adc1fa3f8a66302ba1e4bdd38eaf (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2015-11-12T17:50:37Z (GMT) No. of bitstreams: 2 Dissertação - Lícia Aparecida da Silva - 2015.pdf: 2121079 bytes, checksum: b400adc1fa3f8a66302ba1e4bdd38eaf (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-11-12T17:50:37Z (GMT). No. of bitstreams: 2 Dissertação - Lícia Aparecida da Silva - 2015.pdf: 2121079 bytes, checksum: b400adc1fa3f8a66302ba1e4bdd38eaf (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-08-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The present work describes the development of an analytical method for the removal of contaminant emerging Sodium Diclofenac (DCF) present in aqueous solutions. For the removal thereof, it is used as a natural adsorbent sawdust treated in acid medium. The detection and quantification of the analyte were Performed by High-Performance Liquid Chromatography (English, HPLC). The material was characterized according to the techniques of Infrared Spectroscopy and X-Ray Diffraction. The Point of Zero Charge (PZC) was obtained both for the sawdust treated in acid medium, and for the same in kind, obtaining values of 4.8 and 5.5, respectively. We chose to work with the adsorbent treated with acid in natural pH of the solution (6.43), since the adsorption was quite satisfactory (86%). It was determined the LD figures of merit (0.06 mg L-1) and LQ (0.2 mg L-1). The linearity was determined by construction of standard curves prepared in solvent and prepared curves with water samples fortified with the DCF standard. The obtained correlation coefficient was quite satisfactory (r = 0.9999) and the recovery values were between 86% and 117% to the study drug. It used Full Factorial Planning 23 for optimization of chemical variables that can have an effect on the adsorption process. The results obtained by the Pareto chart showed that the only variable that exerted influence on the adsorption was the mass of adsorbent. Therefore, it was determined by univariate optimization, as being 600 mg. To study the adsorption kinetics, it was determined the equilibration time of 180 min, and following the adsorption pseudosegunda-order model. The isotherm obtained was linearized and the result indicated that the adsorption follows the Langmuir model, ie, chemical adsorption occurs monolayer. / O presente trabalho descreve o desenvolvimento de uma metodologia analítica para a remoção do contaminante emergente Diclofenaco de Sódio (DCF) presente em soluções aquosas. Para a remoção do mesmo, utilizou-se como adsorvente natural a serragem de madeira tratada em meio ácido. A detecção e quantificação do analito foram realizadas por Cromatografia Líquida de Alta Eficiência (do inglês, HPLC). O adsorvente foi caracterizado segundo as técnicas de Espectroscopia de Infravermelho e Difração de Raios-X. O Ponto de Carga Zero (PCZ) foi obtido tanto para a serragem de madeira tratada em meio ácido, como para a mesma in natura, obtendo valores de 4,8 e 5,5, respectivamente. Optou-se por trabalhar com o adsorvente tratado com ácido em pH natural da solução (6,43), visto que a adsorção foi bastante satisfatória (86%). Determinou-se as figuras de mérito LD (0,06 mg L-1) e LQ (0,2 mg L-1). A linearidade foi determinada através da construção de curvas analíticas preparadas em solvente e curvas preparadas com amostras de água fortificadas com o padrão de DCF. O coeficiente de correlação obtido foi bastante satisfatório (r = 0,9999) e os valores de recuperação ficaram entre 86% e 117% para o fármaco em estudo. Utilizou-se Planejamento Fatorial Completo 23 para a otimização das variáveis químicas que podem exercer efeito sobre o processo de adsorção. Os resultados obtidos segundo o gráfico de Pareto demonstraram que a única variável que exerceu influência sobre a adsorção foi a massa do adsorvente. Sendo assim, a mesma foi determinada através de otimização univariada, como sendo de 600 mg. Para o estudo da cinética de adsorção, ficou definido o tempo de equilíbrio de 180 min, e a adsorção seguindo o modelo de pseudosegunda-ordem. A isoterma obtida foi linearizada e o resultado indicou que a adsorção segue o modelo de Langmuir, ou seja, ocorre adsorção química em monocamada.

Made available in DSpace on 2017-07-10T17:40:48Z (GMT). No. of bitstreams: 1 2014_Tese_Herbert_Nacke.pdf: 3662817 bytes, checksum: 26b0dca41181044d14f648fbf6ffe7e3 (MD5) Previous issue date: 2014-02-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work aimed to evaluate the performance of three biosorbents obtained from the bark of fruit (biosorbent C), the endosperm (biosorbent E) and from the endosperm plus seed coat (biosorbent E + T) of Jatropha (Jatropha curcas L.) in the removal of metals chromium (Cr3+), cadmium (Cd2+), copper (Cu2+) and zinc (Zn2+) in aqueous solutions. To elucidate the properties of biosorbents, the characterization by infrared spectroscopy (IR), scanning electron microscopy (SEM) and determination of the point of zero charge (pHPCZ) of the materials was performed. The study of the optimal conditions and mechanisms that control the adsorption of the aforementioned metals by the biosorbents was performed through the influence of the solution pH, the mass of biosorbent, the contact time between the solution and the biosorbent, the initial concentration of metals in solution (adsorption isotherms) and the temperature during adsorptive process (thermodynamics). The adsorption kinetics was evaluated using the mathematical models of pseudofirst and pseudosecond order, Elovich and intraparticle diffusion. The adsorption isotherms were linearized by mathematical models of Langmuir, Freundlich and Dubinin-Radushkevich. Was also performed the comparision of the biosorbents with activated charcoal, since this material is the mainly adsorbent used in the sorption process of metallic contaminants. In the characterization of biosorbents was observed that all three materials have a structure with proteins, lignin, cellulose, hemicellulose, lignocellulose, hydroxyl, carboxylic, carbonyl and phenol groups, which enable bonds with metallic ions in solution. Furthermore, it was observed that the surface morphology of the biosorbents has irregular appearance, indicating a porous surface and good adsorptive capacity. The biosorbents show a pHPCZ between 5 and 6. The optimal conditions for the adsorptive process were: pH of 5.5 for the metals Cr3+ and Cd2+ and 5.0 to Cu2+ and Zn2+, 8.0 g L-1 of biosorbent mass per volume of solution and a contact time between the biosorbents and the contaminated solutions of 60 min for all metals. The results obtained in the adsorption kinetics indicate that for all metals in the study, the biosorbents showed a better fit by pseudosegunda order model, indicating the occurrence of chemical adsorption. Considering the maximum adsorption capacities obtained by the mathematical model of Langmuir, the biosorbent C presents the following order of removal: Cd2+ > Cr3+ > Zn2+ > Cu2+ (29.66; 22.11; 14.85 and 11.54 mg g-1); whereas for the biosorbent E the order was: Cu2+ > Cd2+ > Cr3+ > Zn2+ (20.47; 19.56; 18.20 and 15.88 mg g-1) and for the biosorbent E+T it was obtained: Cd2+ > Cu2+ > Cr3+ > Zn2+ (34.67; 22.91; 22.88 and 16,67 mg g-1). Regarding the adsorption form, the results showed that for all metals the chemisorption controls the adsorptive process, with the occurrence of mono-and multilayers for Cr3+ and monolayers for Cd2+, Cu2+ and Zn2+. Based on the results obtained in this work, it is possible affirm that the three biosorbents derived from the biomass of Jatropha have potential for the remediation of water resources contaminated with the metals Cr3+, Cd2+, Cu2+ and Zn2+, also providing an alternative use of the waste generated in biodiesel production of this species, increasing the sustainability of their supply chain / Este trabalho objetivou avaliar o desempenho de três biossorventes obtidos a partir da casca dos frutos (biossorvente C), do endosperma (biossorvente E) e do endosperma mais tegumento das sementes (biossorvente E+T) de pinhão manso (Jatropha curcas L.) na remoção dos metais cromo (Cr3+), cádmio (Cd2+), cobre (Cu2+) e zinco (Zn2+) de soluções aquosas. Para elucidação das propriedades dos biossorventes foi realizada a caracterização por espectroscopia de infravermelho (IV), microscopia eletrônica de varredura (MEV) e determinação do ponto de carga zero (pHPCZ) dos materiais. O estudo das condições ideais e dos mecanismos que controlam a adsorção dos metais supracitados pelos biossorventes foi realizado por meio da influência do pH da solução, da massa dos biossorventes, do tempo de contato entre a solução e os biossorventes, da concentração inicial dos metais na solução (isotermas de adsorção) e da temperatura durante o processo adsortivo (termodinâmica). A cinética de adsorção foi avaliada por meio dos modelos matemáticos de pseudoprimeira e pseudosegunda ordem, de Elovich e de difusão intrapartícula. As isotermas de adsorção foram linearizadas pelos modelos matemáticos de Langmuir, Freundlich e Dubinin-Radushkevich. Realizou-se ainda a comparação dos biossorventes com carvão ativado, uma vez que este material é o principal adsorvente utilizado em processos de sorção de contaminantes metálicos. Na caracterização dos biossorventes observou-se que os três materiais apresentam em sua estrutura proteínas, lignina, celulose, hemicelulose, lignocelulose, grupos hidroxílicos, carboxílicos, carbonílicos e fenóis, os quais possibilitam ligações com íons metálicos em solução. Além disto, observou-se que morfologia superficial dos biossorventes tem aspecto irregular, indicando uma superfície porosa e com boa capacidade adsortiva. Os biossorventes apresentaram ainda um pHPCZ entre 5 e 6. As condições ideais do processo adsortivo foram: pH da solução de 5,5 para os metais Cr3+ e Cd2+ e 5,0 para o Cu2+ e o Zn2+, 8,0 g L-1 de massa de biossorvente por volume de solução e um tempo de contato entre os biossorventes e as soluções contaminadas de 60 min para todos os metais. Os resultados obtidos na cinética de adsorção indicam que para todos os metais em estudo, os biossorventes apresentaram melhor ajuste pelo modelo de pseudosegunda ordem, indicando a ocorrência de adsorção química. Considerando as capacidades máximas de adsorção obtidas pelo modelo matemático de Langmuir, o biossorvente C apresenta a seguinte ordem de remoção: Cd2+ > Cr3+ > Zn2+ > Cu2+ (29,66; 22,11; 14,85 e 11,54 mg g-1); ao passo que para o biossorvente E a ordem foi: Cu2+ > Cd2+ > Cr3+ > Zn2+ (20,47; 19,56; 18,20 e 15,88 mg g-1) e para o biossorvente E+T obteve-se: Cd2+ > Cu2+ > Cr3+ > Zn2+ (34,67; 22,91; 22,88 e 16,67 mg g-1). A aplicação do modelo de Dubinin-Radushkevich demonstrou que a adsorção de todos os metais pelos biossorventes se dá por quimiossorção, com a ocorrência de mono e multicamadas para o Cr3+ e monocamadas para o Cd2+, o Cu2+ e o Zn2+. Baseado nos resultados obtidos neste trabalho, é possível afirmar que os três biossorventes oriundos da biomassa de pinhão manso apresentam potencial para a remediação de recursos hídricos contaminados com os metais Cr3+, Cd2+, Cu2+ e Zn2+, proporcionando ainda, uma alternativa de uso dos resíduos gerados na produção de biodiesel desta espécie, aumentando a sustentabilidade da sua cadeia produtiva

Equipamentos de plasma são muito utilizados para polimerização de filmes finos, orgânicos e inorgânicos. Filmes finos têm uma vasta gama de aplicações no desenvolvimento de dispositivos MEMS (MicroElectroMechanical Systems), tais como sensores, detectores, pré-concentradores, etc. Portanto, neste trabalho é apresentado um equipamento de polimerização por plasma com características distintas, o que permite seu uso para obtenção de novos filmes finos e/ou compósitos em uma única etapa de fabricação. Os filmes obtidos são formados por partes orgânicas distintas, ou mesmo por regiões adsorventes ou repelentes. Alguns filmes possuem partículas orgânicas em mistura com o filme fino, o que facilita o controle da rugosidade e da área superficial, permitindo seu uso em sistemas de retenção. O projeto do reator permite deposições por plasma introduzindo, simultaneamente e sem interrupção do processo, reagentes incompatíveis em plasma ou mesmo a formação seqüencial de camadas, sem a necessidade de abertura do reator entre as etapas do processo (etapa única). O projeto da câmara de plasma foi simulado usando FEMLAB 3.2® e caracterizado utilizando traçadores. Simularam-se fluxo de gás e partículas além de campo elétrico e magnético. As simulações e resultados experimentais mostraram boa coerência. O fluxo permaneceu sem grande vorticidade em toda a faixa de trabalho e o campo magnético foi adequado para o confinamento do plasma. Foram depositados filmes úteis para desenvolvimento de sensores e adsorventes, resistentes a corrosão ou compósitos. Foram polimerizados por plasma: hexametildisilazana (HMDS) com produção de filme hidrofóbico e adsorvente; metil-nonafluoro(iso)butil-éter (HFE 7100®), obtendo-se filmes com características adsorventes, mas oleofóbicos e medianamente hidrofílicos e 2,3-dihidrodecafluoropentano (Vertrel®) com formação de filmes com boa resistência à corrosão além de facilidade de adsorção. Partículas de amido foram recobertas com filme a base de HMDS e de HFE 7100 e mostraram boas propriedades para retenção de moléculas orgânicas de tamanho médio. Neste equipamento, filmes à base de HMDS mostraram-se úteis para retenção de compostos orgânicos, em fase líquida ou gasosa. Espectroscopia de infravermelho, da produção simultânea de filme a base de HMDS e de Vertrel, mostrou espécies de flúor e silício e eventualmente CO, porém CHn é a espécie em menor intensidade. Microscopia óptica dos filmes revela boa aderência em metais e acrílico e, para os fluorados, resistência a solventes orgânicos e à exposição a solução aquosa ácida ou básica. Intermixing e dupla camada só são obtidas em condições muito estreitas, entretanto, existe a possibilidade de formação de ilhas. Microbalança de quartzo mostrou que 2-propanol permeia no filme formado por intermixing de HFE7100 e HMDS, porém não existe nenhuma sensibilidade a n-hexano. Um microreator fabricado, com microcanais de 73 cm de comprimento, pôde reter aproximadamente 9.10-4 g/cm2 de 2-propanol em fase gasosa, usando-se o filme obtido por intermixing. Portanto, o filme é um bom candidato a preconcentração de compostos orgânicos voláteis em ambiente corrosivo. Uma microestrutura produzida com as partículas de amido recobertas foi proposta para avaliar em fluxo contínuo a contaminação de soluções aquosas. Foi possível determinar a contaminação na proporção de 1:200 em vol. de 2-propanol, com saturação em 25% em vol. / Plasma equipment is quite useful for polymerization of organic/inorganic thin films. Thin films have a vast range of applications as sensor, detectors, preconcentrators and so on. In this work plasma polymerization equipment is presented with innovative characteristics that it should allow the obtaining of new fine films and composites. These films can be formed not only with different organic parts but also with areas adsorbents and repellents. Some films will present particles, ceramic or metallic, in mixture with the organic thin film, which will facilitate the control of the roughness and of the superficial area, allowing its use in retention systems. The design of the reactor allows plasma depositions introducing more than one reactant simultaneously and without process interruption, or even sequential formation of layers, without the need of chamber opening among process steps, i. e., in a single step. It was simulated and characterized parts of the equipment, such as: gas flow and particles admission; electric and magnetic fields profiles. Therefore, a new plasma chamber with atypical geometry was simulated and projected and manufactured to obtain multiple layers and/or composites. The simulation and experimental results showed good coherence. The gas flow stayed without great vorticity in the all range of the work and the magnetic field was adequate for plasma confinement. As the main objective of this work is the production and characterization of news materials, thin films were deposited with purpose of being adsorbent; corrosion resistant; and composite, all useful for development of sensor. It was plasma polymerized: hexamethyldisilazane (HMDS), a well known organic silicon compound, methyl nonafluoro (iso) butyl ether: should have good resistance to the corrosion besides easiness of adsorption; and 2,3-dihydrodecafluoropentane: adsorbent, hydrophobic and oleophobic. Particles (starch 5mm), were recovered with HMDS and HFE 7100 and showed good properties for retention of medium size organic molecules, such as dye. The results were useful for retention of organic compounds, in liquid or gaseous phase. Not only, HMDS is possible in any configuration of electrodes and the obtained films are hydrophobic but also, fluorinated compounds polymerized, however, intermixing and couple layer is only obtained in very narrow conditions, but the possibility of formation of islands exists. The chemical characterization was determined for infrared spectroscopy, it showed species composed by fluorocompounds, and eventually CO, however CHn is the smallest species. The hydrophobic character, organophylic and oleophobic were obtained through contact angle measurements. Optical Microscopy not only reveals good adherence in metals and acrylic but also resistance to organic solvents, acid and exhibition of basic aqueous solution. A manufactured micro-reactor, with micro channels of 73 cm of length, can keep approximately 9.10-4 g/cm2 of 2-propanol in gaseous phase. Therefore, the film is a good candidate in organic preconcentration of volatile organic compounds even on corrosive environment.

Les exploitations d’argiles kaoliniques réfractaire d’Água Limpa/Brésil et de kaolins de couchage de Rio Capim/Brésil laissent des résidus d’exploitation en très grands tonnages. Dans la perspective d’une valorisation plus complète assurant un développement durable de l’industrie extractive, on a envisagé d’utiliser ces argiles résiduelles dans la fabrication de zéolites. On a obtenue dès une durée de synthèse de 24h, une zéolite 4A très proche de sa définition théorique. Le rendement de synthèse est meilleur avec les produits de Rio Capim. Le volume nanoporeux de la zéolite 4A est inaccessible à l’azote mais accessible à la molécule d’eau. Les zéolites synthétisées ont été testées comme adsorbants cationiques pour le cuivre, le plomb, le cadmium, le zinc, le magnésium, potassium et mercure. La rétention a voisine 60% du remplissage théorique pour toutes les espèces testées, sauf pour le cuivre où elle dépasse la capacité théorique et pour le mercure où elle est très faible. / Working Kaolinic refractory clays from Água Limpa (Minas Gerais) and paper coating kaolins from Rio Capim (Pará) - Brazil throw over very large amounts of mining residues. With the outlook of a more complete beneficiation, aiming at a sustainable development of mineral industry, the use of these residual clays has been considered for manufacturing zeolites. For a synthesis time of only 24h, a zeolite 4A very close to its theoretical definition is obtained.The nano-porous volume of the zeolite 4A is inaccessible to nitrogen molecules, but accessible to water molecules. Synthesised zeolites have been tested as cationic adsorbents of Cu, Pb, Cd, Zn, Mg, K and Hg. The retention is better for materials derived from Rio Capim Kaolins. The retention is close to 60% of the theoretical completion of the exchange capacity in all cases, except for copper for which the retention exceeds the capacity, and mercury for which the retention is very low.

Adsorbent materials for gas purification have been studied and developed for application in many areas. It is known that a single adsorbent may not adequately control multiple contaminants. Therefore, the development of adsorbent materials has accelerated over the past two decades, and is today an area attracting a lot of attention. In view of the global environmental movement for clean air, the development of improved sorbents will help address new challenges that cannot efficiently be met with the generic sorbents that are presently commercially available. On the other hand, the utilization of these new sorbents for specific applications within the area of molecular filtration remains largely unexplored. This thesis presents a synthesis of new sorbent materials, and the characterization and application of these materials for molecular filtration. Commercial adsorbents have been used for benchmarking for the pore properties, the applicability, and the performance of these new adsorbents. A double metal-silica adsorbent has been synthesized. The preparation procedure is based on the use of sodium silicate coagulated with various ratios of magnesium and calcium salts which yields micro-meso porous structures in the resulting material. The results show that molar ratios of Mg/Ca influence the pore parameters as well as the structure and morphology. The bimodal pore size can be tailored by controlling the Mg/Ca ratio. The effect of thermal treatment on pore parameters of these adsorbents has been investigated. The results show that heat treatment had a notable effect on the pore parameters, and that the pore structure was thermally stable even at 600°C.  A synthesis method has also been developed for the preparation of carbon-silica composites. The method involves a number of routes, which can be summarised as addition of activated carbon particles to (I) the paste, (II) the salt solution, or (III) with the sodium silicate solution. In route II and III the activated carbon is present also before coagulation. The routes presented here leads to carbon-silica composites possessing high micro porosity, meso porosity as well as large surface areas. The increase in micro porosity and surface areas was linear with carbon content. The results shows further that pore size distribution may be tailored based on the route of addition of the carbon particles. Following route I and III a wide pore size (1-30nm) was obtained where as by route II a narrow pore size (1-4nm) was observed. KOH or KMnO4 modified MgCa adsorbent varieties were also prepared. The impregnationwas performed by either a direct synthesis or post-synthesis procedure. Potassium hydroxide and potassium permanganate have been chosen as impregnate chemicals. Results revealed that theimpregnate amount significantly affected both the structural and the gas adsorption characteristics of the impregnated MgCa adsorbents. The properties of double- metal adsorbents, impregnated adsorbents and carbon-silica composites were characterized by various methods (X-ray diffraction, scanning electron microscopy, thermo gravimetric analysis, and nitrogen adsorption at 77K) to study the material structure and morphology, thermal stability, ignition temperature and porous parameters with regard to surface area, pore size, pore size distribution and porosity volume, which is important for optimizing their use in many practical application. The up-take performance of adsorbents for dynamic adsorption of SO2, H2S and toluene was performed in a system similar to the setup usedin ASHRAE 145.1. Finally the applicability and performance of the impregnated modified MgCa-silica adsorbents and composites have been evaluated for H2S, SO2 and toluene adsorption and compared to some commercial adsorbent materials. Results revealed that a potassium permanganate modified MgCa-adsorbent has a H2S adsorption capacity in the range of 0.08-3.19 wt % at 50% efficiency, and that the uptake capacity was relative to the amount of potassiumpermanganate loading. Moreover, KOH modified MgCa-adsorbent shows highest SO2 adsorption capacity (1.7 wt %) which is 3.47 times higher than commercial alumina impregnate with potassium permanganate (0.49 wt %). Carbon-silica composites on the other hand shows adsorption of toluene and high adsorption capacity was obtained when carbon content was 45 wt %. The results further shows that a composite with 45 wt % carbon and obtained via route I present the highest toluene adsorption capacity ( 27.6 wt % relative to carbon content) at 0% efficiency. The large uptake capacity of this composite was attributed to the presence of high microporosity volume and a wide (1-30nm) bimodal pore system consisting of extensive mesopore channels (2-30nm) as well as large surface area. These capacity values of carbon-silica composites are competitive to results obtained for commercial coconut based carbon (31 wt %), and better than commercial alumina-carbon composite. / QC 20110405