Orientador: Sidney José Lima Ribeiro / Banca: Marie-Joelle Menu / Banca: Lucas Alonso Rocha / Banca: Lauro June Queiroz Maia / Banca: Michel Wong Chi Man / Banca: Marc Verelst / Banca: Isabelle Gautier-Luneau / Resumo: The design of heterobimetallic luminescent complexes has gained growing interest in recent years due to their unique photophysical properties. More specifically, the development of heterobimetallic complexes using d-block chromophores to sensitize the near-infrared (NIR) emission of lanthanide complexes (such as Nd(III) and Yb(III)) has received significant attention taking into account their longer emission wavelengths and the interest of the NIR emission which penetrates human tissue more effectively than UV light. These properties give them potential applications in medical diagnostics or biomedical assays. Transitions to excited state levels of transition metal complexes occurring in the visible and characterized by large absorption coefficients, could efficiently sensitize f-f levels of Ln(III) ions. In this work new d-f heterobimetallic complexes containing silylated ligands were prepared supported on silica materials. [Ru(bpy)2(bpmd)]Cl2 (labeled Ru), [Ru(bpy)(bpy-Si)(bpmd)]Cl2 (labeled RuL) and [Ln(TTA-Si)3] (labeled LnL3) and d-f heterobimetallic complexes, Ru-LnL3 and Ln-RuL (Ln = Nd3+, Yb3+) were prepared. Structural characterization was carried out by Raman Scattering, 1H and 13C NMR spectroscopies. Results obtained from 1H-13C HMBC and HSQC correlation NMR spectra confirm the formation of proposed complexes. Photophysical properties studies highlight the efficiency of Ru-Ln energy transfer processes in NIR-emitting lanthanide complexes mediated by conjugated brid... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: ABSTRACT The design of heterobimetallic luminescent complexes has gained growing interest in recent years due to their unique photophysical properties. More specifically, the development of heterobimetallic complexes using d - block chromophores to sensitize the near - infrared (NIR) emission of lanthanide complexes (such as Nd(III) and Yb(III)) has received significant attention taking into account their longer emission wavelengths and the interest of the NIR emission which pene trates human tissue more effectively than UV light. These properties give them potential applications in medical diagnostics or biomedical assays. Transitions to excited state levels of transition metal complexes occurring in the visible and characterized by large absorption coefficients, could efficiently sensitize f - f levels of Ln(III) ions. I n this work new d - f heterobimetallic complexes containing silylated ligands were prepared supported on silica materials. [Ru(bpy) 2 (bpmd)]Cl 2 (labeled Ru ), [Ru(bpy)(bpy - Si)(bpmd)]Cl 2 (labeled RuL ) and [Ln(TTA - Si) 3 ] (labeled LnL3 ) and d - f heterobimetallic complexes, Ru - LnL3 and Ln - RuL (Ln = Nd 3+, Yb 3+ ) were prepared. Structural characterization was carried out by Raman Scattering, 1 H and 13 C NMR spectroscopies . Results obtained from 1 H - 13 C HMBC and HSQC correlation NMR spectra confirm the formation of proposed complexes. Photophysical properties studies highlight the efficiency of Ru - Ln energy transfer processes in NIR - emitting lanthanide complexes mediated by conjugated bridging ligand (2,2' - bipyrimidine). Lifetime measurements were carried out and values of quantum yield for energy transfer (  ET ) between 30 and 84 % could be evaluated.  ET of 7 3 .4 % obtained for the Yb - RuL complex is the largest value reported for Ru(II) - Yb(III) heterobimetallic complexes so far. Grafting on different silica matrix was also demonstrated... / Doutor

CORREIA, L. M. Fe2O3 ou Co3O4 suportados em sílicas mesoporosas modificadas com NH4F e Ti para adsorção de benzotiofeno e reação de oxidação catalítica seletiva parcial de H2S a S. 2017. 233 f. Tese (Doutorado em Engenharia Química)-Centro de Tecnologia, Universidade Federal do Ceará, Fortaleza, 2017. / Submitted by Hohana Sanders (hohanasanders@hotmail.com) on 2017-10-03T18:25:12Z No. of bitstreams: 1 2017_tese_lmcorreia.pdf: 3519700 bytes, checksum: 80fb75064a529c39bee1587404389fd8 (MD5) / Approved for entry into archive by Marlene Sousa (mmarlene@ufc.br) on 2017-11-08T14:44:39Z (GMT) No. of bitstreams: 1 2017_tese_lmcorreia.pdf: 3519700 bytes, checksum: 80fb75064a529c39bee1587404389fd8 (MD5) / Made available in DSpace on 2017-11-08T14:44:39Z (GMT). No. of bitstreams: 1 2017_tese_lmcorreia.pdf: 3519700 bytes, checksum: 80fb75064a529c39bee1587404389fd8 (MD5) Previous issue date: 2017-07-31 / The presence of sulfur (S) in automotive fuels must be retrain, once it generates air pollution and promotes damage to the motor (corrosion), affecting the health of living beings. The conventional process of hydrodesulfurization (HDS) for sulfuric compounds removal, used by petrochemical industries, generates large amount of H2S, which can be used in selective partial oxidation reaction of H2S to S. The HDS treatment process is not effective to remove refractory compounds at low concentrations of S, making polish techniques, such as adsorption, necessary due to environmental constraints increase. This situation has led to a need of deeper research in the area of sulfur compounds removal in fossil fuels (gas and diesel). Thus, the development of methodologies to prepare and characterize new adsorbents with high sulfur removal are necessary. The adsorption of BT (standard organic molecule contained in gas and diesel) was investigated using a regular mesoporous silica SBA-15 type and modified with NH4F, and impregnated with Fe and Co respectively. The experiments were done in batch, with different initial BT concentrations (3-15 mmol.L-1) at different temperatures (30 °C, 40 °C and 50 °C). In the second part of the research, the H2S was partially oxidized to S and SO2 using a tubular fixed bed catalytic reactor, containing mesoporous silica HMS, SBA-15, and MCM-41 modified with NH4F and Ti, and respectively Fe2O3 and Co3O4. The catalytic tests were conducted at 180 °C and 170 oC. Reactional conditions were a catalyst mass of 100 mg (40-60 mesh), operating with a 125 mL.min-1 total flow, with molar ratio H2S/Air/He (1/5/94). The brackets, adsorbents and active phases of mesoporous catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), adsorption and desorption isotherms at -196°C, x-ray photoeletronic spectroscopy (XPS), Fourier transform infrared (FTIR), Elemental analysis (CHNS) and spectroscopy of UV-visible region. The results show that mycotoxin adsorbents are promising for the hydrodesulfurization process for BT removal, especially, the sample (15Co/SBA-15/NH4F). All the prepared catalysts are active and promising for the elementary S production. The most stable catalyst was 15Fe/MCM-41, obtaining conversion values of H2S (89.72%), selectivity of S (96.19%), and selectivity of SO2 (3.81%) at 180 °C and 360 min of reaction time in the H2S to S selective oxidation partial reaction in gas phase / A presença de enxofre (S) nos combustíveis automotivos deve ser combatida, uma vez que gera a poluição atmosférica e traz prejuízos ao motor (corrosão), afetando também à saúde dos seres vivos. O processo convencional de hidrodessulfurização (HDS) para remoção dos compostos de S, utilizado pelas indústrias petroquímicas, gera elevada quantidade de H2S, o qual pode ser utilizado na reação de oxidação seletiva parcial de H2S a S. O processo de tratamento por HDS não é eficaz para remoção de compostos refratários em baixas concentrações de S, o que torna necessário a técnicas de acabamento como a adsorção, devido a um aumento nas restrições ambientais. Essa situação tem levado a uma necessidade de maiores pesquisas na área de remoção de sulfurados nos combustíveis (gasolina e diesel). Assim, busca-se desenvolver metodologias para preparar e caracterizar novos adsorventes com elevada capacidade de remoção de enxofre. A adsorção de BT (molécula orgânica modelo contida na gasolina e diesel) foi investigada utilizando-se sílicas mesoporosas do tipo SBA-15 e modificadas com NH4F, e impregnadas respectivamente com Fe e Co. Os experimentos foram feitos em batelada, com diferentes concentrações iniciais de BT (3-15 mmol/L) e temperaturas distintas (30 oC, 40 oC e 50 oC). Na segunda parte da pesquisa o H2S foi parcialmente oxidado a S e SO2 utilizando um reator catalítico de leito fixo do tipo tubular, contendo sílica mesoporosa do tipo HMS, SBA-15, e MCM-41 modificadas com NH4F e Ti, e respectivamente Fe2O3 e Co3O4. Os testes catalíticos foram conduzidos a uma temperatura de reação de 180 ºC e 170 oC. As condições reacionais foram massa do catalisador de 100 mg (40-60 mesh), operando com uma vazão total de 125 mL min-1, com razão molar H2S/Ar/He (1/5/94). Os suportes, adsorventes e as fases ativas dos catalisadores mesoporosos foram caracterizados por difração de raios-X (DRX), microscopia eletrônica de transmissão (MET), isotermas de adsorção e dessorção a -196 oC, espetroscopia fotoeletrônica de raios-X (XPS), infravermelho com transformada de Fourier (FTIR), análise elementar (CHNS) e espectroscopia da região do UV-visível. Os resultados demonstram que os adsorventes são promissores para o processo de hidrodessulfurização para a remoção da molécula de BT, especialmente, a amostra (15Co/SBA-15/NH4F). Todos os catalisadores preparados são ativos e promissores para produção de S elementar. O catalisador mais estável foi 15Fe/MCM-41, obtendo-se valores de conversão de H2S (89,72%), seletividade a S (96,19%), e seletividade a SO2 (3,81%) na temperatura de 180 oC e tempo reacional de 360 min na reação parcial de oxidação seletiva de H2S a S em fase gás

Made available in DSpace on 2014-06-11T19:35:07Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-04-12Bitstream added on 2014-06-13T18:46:22Z : No. of bitstreams: 1 rocha_la_dr_araiq.pdf: 3758896 bytes, checksum: 8f9b1dddc8f92a0c77915bd317de357f (MD5) / Partículas esféricas de sílica mesoporosa foram obtidas a partir da síntese “template” pelo processo de pirólise de aerossol. O processo foi otimizado para a obtenção de materiais mesoporosos sem resíduos orgânicos e preparados em uma única etapa, eliminando assim, a longa etapa de remoção do surfactante na metodologia tradicional (tratamento térmico ou extração soxhlet, podendo durar dezenas de horas). A otimização do processo de pirólise de aerossol proposta nesta tese reduziu este tempo para apenas alguns minutos. Os materiais apresentaram uma área superficial (BET) de até 1028 m2 .g-1 , com volume de poros (BJH) de 0,58 cm3 .g-1 . Os difratogramas de raios-X indicaram um alto grau de organização com um arranjo hexagonal de poros, confirmado também pela microscopia eletrônica de transmissão. Além disto, bandas características de grupos orgânicos não foram observadas nos espectros de absorção na região do infra-vermelho para as amostras obtidas acima de 600ºC. Amostras dopadas com íons Eu3+ também foram preparadas durante a tese. A análise por espectroscopia de luminescência, para íons Eu3+ , indicou que o íon está encapsulado nos canais mesoporosos sem prévia modificação química da matriz. Posteriormente, moléculas de 1,10- Fenantrolina foram coordenadas ao íon Eu3+ aumentando a faixa espectral de excitação do íon (efeito antena). Além disto, partículas luminescentes também foram obtidas pela incorporação do complexo Eu(fod)3 ou rodamina-B nos poros das matrizes. Finalmente, testes de recobrimento (core shell, SiO2 mesoporoso-SiO2) das partículas luminescentes foram realizados e os resultados indicaram que independentemente da espessura obtida pelo processo de recobrimento, o grau de organização dos poros e a fotoluminescência não sofreram alterações / Spherical mesoporous silica particles were obtained using the template synthesis by spray pyrolysis process. The process was optimized for the preparation of the mesoporous materials in one-pot route without organic residues, eliminating thus, the long process of removal of the surfactant, usually used in the available methods (heat treatment or soxhlet extraction, which require several hours or days). The one- pot route proposed in this thesis reduced the extraction process to only a several minutes. These materials presented a surface area value (BET) of 1028m2 .g-1 and pore volume (BJH) was 0,58 cm3 .g-1 . The X-ray diffraction patterns and the transmission electronic micrographs show an ordered typical p6mm 2D hexagonal mesostructure. Characteristics bands of organic groups were not observed in the infra-red absorption spectra for the samples obtained at 600ºC. Moreover, SiO2 mesoporous doped with Eu3+ ions were also prepared. Luminescence data suggest that the Eu3+ ions were successful encapsulated into the channels of mesoporous silica without any preliminary chemical modification of the matrix. Moreover, extra ligands such as 1,10-Phenantroline can be further coordinated, increasing the spectral range excitation (antenna effect). Furthermore, luminescent particles were also prepared by the wet impregnation of Eu(fod)3 complex and rhodamine-B molecules. Finally, tests of coating (core shell, SiO2 mesoporous-SiO2) of luminescent particles had been carried through and the The results obtained show spherical shape and the observation of a highly ordered hexagonal array of mesochannels further confirms the 2D hexagonal p6m structure. Luminescence results reveal that rhodamine-B has been successfully encapsulated into the channels of mesoporous particles. Silica coating has been observed in TEM measurements

Made available in DSpace on 2016-06-02T19:56:47Z (GMT). No. of bitstreams: 1 4360.pdf: 7212224 bytes, checksum: 710c4dcdcee04da2d2dac142c9fe7866 (MD5) Previous issue date: 2012-03-30 / Universidade Federal de Sao Carlos / The need to develop a catalyst capable of processing heavy oil fractions, which is extracted from deeper wells, is essential. This concern has become more remarkable with the discovery of new oil fields in Brazil. This expectation, which will sustain the country's independence concerning to the production of oil and its derivatives, has led to profound changes in the scientific and technological strategies of Petrobras, in order to provide the necessary knowledge for the processing and production of Petroleum derivatives, attending the various quality and environmental constraints, as well as provide raw material for the growing demand of the petrochemical industry. In this complex context, the study of catalysts for obtaining light hydrocarbons by cracking of heavy fractions of petroleum became an important strategy. The zeolites used in this process, in despite of be very actives, have restrictions regarding to internal diffusion of bulky molecules, which must be overcome. The present research is inserted in this background. The studies were directed in a first step to check the activity and selectivity of acid zeolites in the cracking of cyclohexane, used as a model molecule. The evaluation of H-ZSM-5, H-mordenite, H-Ferrierite, H-Beta and USY, showed that the activity was greatly influenced by the number of external sites and the great potential of the H-Beta zeolite to be applied in naphthenic cracking, because it showed high activity and a better yield to light olefins than USY zeolite, used commercially. The H-ZSM- 5 zeolite confirmed their high potential as catalyst for this process. The cracking of cyclohexane on the H-zeolites also showed the influence of the external sites. Expecting to overcome the diffusional limitations in microporous commented above, in a second step, the study was focused on the preparation of solids containing micro and mesoporous. The method of nanoclusters ZSM-5 zeolite aggregation in a mesostructure matrix was used, resulting in a solid composed by a segregated material of MCM-41 and ZSM-5, but with high catalytic potential. In the materials characterization were used X-ray diffraction (XRD) at low and wide angles, scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), temperature-programmed desorption of NH3 (TPD-NH3), N2 Physisorption and nuclear magnetic resonance of Al27 (NMR Al27). / A necessidade de se desenvolver catalisadores com capacidade para o processamento de frações pesadas do petróleo, o qual é extraído de poços cada vez mais profundos, é crucial. Esta preocupação tem se tornado mais acentuada com a descoberta de novas jazidas de petróleo no Brasil. Tal expectativa, que sustentará a independência do país em relação à produção de petróleo e seus derivados, vem produzindo profundas mudanças nas estratégias científico-tecnológicas da Petrobras, no sentido de dotar a empresa do conhecimento necessário para o processamento e produção de derivados de petróleo que atendam as diversas restrições de qualidade e ambientais, assim como de fornecer matérias prima para a crescente demanda do setor petroquímico. Nesse complexo contexto, o estudo de catalisadores para a obtenção de hidrocarbonetos leves através do craqueamento de frações pesadas de petróleo, reveste-se de uma importância estratégica. As zeólitas utilizadas nesse processo, apesar de serem muito ativas, possuem restrições referentes à difusão interna de moléculas volumosas, que precisam ser superadas. É nesse cenário que se insere a presente pesquisa. Os estudos foram dirigidos numa primeira parte a verificar a atividade e seletividade de zeólitas ácidas no craqueamento de cicloexano, utilizado como molécula modelo. Os resultados da avaliação das zeólitas H-ZSM-5, H-Mordenita, H-Ferrierita, H-Beta e USY, mostraram o grande potencial da zeólita H-Beta para ser aplicada no craqueamento de hidrocarbonetos naftênicos, pois apresentou um rendimento a olefinas leves superior ao da zeólita USY, utilizada comercialmente. A zeólita H-ZSM-5, por outro lado, ratificou seu alto potencial como catalisador para esse processo. O craqueamento de cicloexano sobre as H-zeólitas consideradas mostrou, também, que a atividade foi muito influenciada pelos sítios externos. Com a expectativa de superar as limitações para a difusão em microporos acima comentada, numa segunda etapa, o estudo se concentrou na preparação de sólidos contendo micro e mesoporos. Foi utilizado o método de agregação de nanoclusters de zeólita ZSM-5 em uma matriz mesoestruturada, que resultou num material composto por partículas segregadas de MCM-41 e ZSM-5, porém com grande potencial catalítico. Na caracterização dos materiais foram utilizadas Difratometria de raios X em pequenos e grandes ângulos, Microscopia Eletrônica de Varredura, Espectroscopia de Energia Dispersiva de Raios X, Termodessorção Programada de Amônia, Fisissorção de N2 e Ressonância Magnética Nuclear de 27Al.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-01-20T21:00:39Z No. of bitstreams: 1 AlexsandraRodriguesDoNascimento_TESE.pdf: 3128857 bytes, checksum: db683b893d3db23b5af91852c4aed0e3 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-01-21T20:23:04Z (GMT) No. of bitstreams: 1 AlexsandraRodriguesDoNascimento_TESE.pdf: 3128857 bytes, checksum: db683b893d3db23b5af91852c4aed0e3 (MD5) / Made available in DSpace on 2016-01-21T20:23:04Z (GMT). No. of bitstreams: 1 AlexsandraRodriguesDoNascimento_TESE.pdf: 3128857 bytes, checksum: db683b893d3db23b5af91852c4aed0e3 (MD5) Previous issue date: 2014-09-23 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Diversos materiais est?o atualmente em estudo para o processo de captura de CO2, a exemplo dos ?xidos met?licos e ?xidos met?licos mistos, ze?litas, materiais carbon?ceos, estruturas metal-org?nicas (MOF?s), organos?lica e superf?cies de s?lica modificadas. Neste trabalho, analisou-se a capacidade de adsor??o de CO2 em materiais mesoporosos de diferentes estruturas, como o MCM-48 e SBA-15, sem impregna??o e impregnados com n?quel nas propor??es 5 %, 10 % e 20 % (m/m), denominados como 5Ni-MCM-48, 10NiMCM-48, 20Ni-MCM-48 e 5Ni-SBA-15, 10Ni-SBA-15, 20Ni-SBA-15. Os materiais foram caracterizados atrav?s das an?lises de difra??o de raios X (DRX), an?lise t?rmica (TG e DTG), espectroscopia na regi?o do infravermelho com transformada de Fourier (FT-IR), adsor??o e dessor??o de N2 (BET) e microscopia eletr?nica de varredura (MEV) com EDS. O processo de adsor??o foi realizado variando-se a press?o de 100 - 4000 kPa e mantendo-se a temperatura constante e igual a 298 K. Na press?o de 100 kPa, as maiores concentra??es de adsor??o ocorreram para os materiais 5Ni-MCM-48 (0,795 mmol g-1 ) e SBA-15 (0,914 mmol g -1 ) n?o impregnado, e, na press?o de 4000 kPa, para os materiais MCM-48 (14,89 mmol g-1 ) e SBA-15 (9,97 mmol g-1 ) n?o impregnados. Os resultados mostraram que a capacidade de adsor??o varia positivamente com a ?rea espec?fica, no entanto, apresenta uma depend?ncia direta com o tipo e geometria dos canais da estrutura porosa. Os dados obtidos foram ajustados atrav?s dos modelos de Langmuir e Freundlich e os par?metros termodin?micos avaliados foram energia livre de Gibbs e entropia do sistema de adsor??o / Several materials are currently under study for the CO2 capture process, like the metal oxides and mixed metal oxides, zeolites, carbonaceous materials, metal-organic frameworks (MOF's) organosilica and modified silica surfaces. In this work, evaluated the adsorption capacity of CO2 in mesoporous materials of different structures, such as MCM-48 and SBA- 15 without impregnating and impregnated with nickel in the proportions 5 %, 10 % and 20 % (m/m), known as 5Ni-MCM-48, 10Ni-MCM-48, 20Ni-MCM-48 and 5Ni-SBA-15, 10NiSBA-15, 20Ni-SBA-15. The materials were characterized by means of X-ray diffraction (XRD), thermal analysis (TG and DTG), Fourier transform infrared spectroscopy (FT-IR), N2 adsorption and desorption (BET) and scanning electron microscopy (SEM) with EDS. The adsorption process was performed varying the pressure of 100 - 4000 kPa and keeping the temperature constant and equal to 298 K. At a pressure of 100 kPa, higher concentrations of adsorption occurred for the materials 5Ni-MCM-48 (0.795 mmol g-1 ) and SBA-15 (0.914 mmol g-1 ) is not impregnated, and at a pressure of 4000 kPa for MCM-48 materials (14.89 mmol g-1) and SBA-15 (9.97 mmol g-1) not impregnated. The results showed that the adsorption capacity varies positively with the specific area, however, has a direct dependency on the type and geometry of the porous structure of channels. The data were fitted using the Langmuir and Freundlich models and were evaluated thermodynamic parameters Gibbs free energy and entropy of the adsorption system

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-30T22:35:16Z No. of bitstreams: 1 DanielleDeOliveiraMaia_TESE.pdf: 2480138 bytes, checksum: 11e89b7c4d42403108c704fd453975d5 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-01T20:04:06Z (GMT) No. of bitstreams: 1 DanielleDeOliveiraMaia_TESE.pdf: 2480138 bytes, checksum: 11e89b7c4d42403108c704fd453975d5 (MD5) / Made available in DSpace on 2016-06-01T20:04:06Z (GMT). No. of bitstreams: 1 DanielleDeOliveiraMaia_TESE.pdf: 2480138 bytes, checksum: 11e89b7c4d42403108c704fd453975d5 (MD5) Previous issue date: 2015-07-23 / SBA-15 s?o materiais mesoporosos, que possuem uma rede de canais e poros de tamanho bem definido na escala nanom?trica, al?m de outras caracter?sticas, tais como, elevada estabilidade t?rmica e ?rea superficial. Essa arquitetura particular de poros torna esses materiais promissores na ?rea de ancoramento de uma variedade de compostos na matriz da s?lica resultando em aplica??es nas diversas ?reas, dentre elas, na cat?lise. Nesse trabalho, foram sintetizados complexos de Base de Schiff com n?quel (II) para serem ancorados na SBA-15 funcionalizada com 3-cloropropiltrimet?xisilano realizando um estudo da estabilidade t?rmica desses compostos. Ap?s a s?ntese dos complexos, estes foram caracterizados por an?lise elementar (CHN), ponto de fus?o, condutividade, susceptibilidade magn?tica, espectroscopia de absor??o na regi?o do UV-vis?vel, espectroscopia de absor??o na regi?o do infravermelho e an?lises t?rmicas (TG/DTG). A an?lise elementar sugere que os complexos apresentam as seguintes f?rmulas qu?micas gerais: [Ni(C18H19N3O2)].2CH3COO.H2O, [Ni(C20H23N3O2)(2Cl)].2H2O, [Ni(C19H20N3O2)(2Cl)].3H2O, sendo L1= C18H19N3O2, L2= C20H23N3O2, L3 = C19H20N3O2. Na espectroscopia de absor??o na regi?o do UV - vis?vel e infravermelho dos complexos foi evidenciada a coordena??o metal - ligante. Ap?s caracteriza??o dos complexos, estes foram ancorados no material mesoporoso. A caracteriza??o desses materiais foi realizada por difra??o de raios - X, fluoresc?ncia de raios - X, adsor??o e dessor??o de N2, espectroscopia de absor??o na regi?o do infravermelho e an?lises t?rmicas (TG/DTG). No DRX foram observados tr?s picos principais de difra??o, cujos ?ndices de Miller s?o (100), (110) e (200), mostrando que mesmo ap?s a ancoragem, os materiais mesoporosos n?o perderam suas caracter?sticas estruturais. As porcentagens dos elementos (n?quel, cloro e s?lica) encontrados nos materiais atrav?s da an?lise de fluoresc?ncia de raios - x mostraram que os complexos foram ancorados nos poros da s?lica. Atrav?s da adsor??o e dessor??o de N2, foram observadas que os materiais apresentaram isoterma do tipo IV e histerese do tipo H1 caracter?sticos dos materiais mesoporos. Na espectroscopia de absor??o na regi?o do infravermelho, os materiais ancorados apresentaram bandas caracter?sticas dos ligantes (Base de Schiff) e da s?lica evidenciando o sucesso da ancoragem. Na an?lise t?rmica, foram observadas a decomposi??o de ?gua adsorvida, ?gua coordenada, aminas, arom?ticos, ligantes, cloropropiltrimet?xisilano e o aumento na estabilidade t?rmica das s?licas ancoradas com complexos comparado ao complexo livre. / SBA-15 are mesoporous materials, having a network of channels and well defined pore size in the nanometer range, as well as, other features such as high thermal stability and surface area. This particular pore architecture makes these promising materials in the anchoring area of a variety of compounds in the silica matrix resulting in applications in various fields, among them, in catalysis. In this work, complexes were synthesized Schiff base with nickel (II) to be anchored in the functionalized SBA-15 3 ? chloropropyltrimethoxysilane and a study of the thermal stability of these compounds. After synthesis of the complexes, they were characterized by elemental analysis (CHN), melting point, conductivity, magnetic susceptibility, absorption spectroscopy in the UV-visible region absorption, spectroscopy in the infrared region and thermal analysis (TG/DTG). Elemental analysis suggests that the complexes have the general formula chemical: [Ni(C18H19N3O2)].2CH3COO.H2O, [Ni(C20H23N3O2)(2Cl)].2H2O, [Ni(C19H20N3O2)(2Cl)].3H2O, and L1= C18H19N3O2, L2= C20H23N3O2, L3 = C19H20N3O2. In absorption spectroscopy in UV - visible and infrared complexes was evidenced the coordination metal - ligand. After characterization of the complexes, confirming the metal - ligand coordination, they have been anchored in the mesoporous material. The characterization of these materials were made by x- ray diffraction, x- ray fluorescence, N2 adsorption and desorption spectroscopy, the infrared spectroscopy and thermal analysis (TG/DTG). XRD analysis revealed three main diffraction peaks, whose Miller indices are (100), (110) and (200), showing that even after the anchoring, the mesoporous materials do not lose their structural characteristics. The percentages of the elements (nickel chloride and silica) found in the anchored materials through the x-ray fluorescence analysis showed that the complexes were anchored in the pores of the silica. Through adsorption and desorption of N2, we observed that the materials presented isotherm type IV and type H1 hysteresis characteristic of mesoporous materials. In the infrared spectroscopy, the materials showed characteristic bands of ligands (Schiff base) and silica demonstrating the success of the anchor. In the thermal analysis (TG/DTG), there were observed the decomposition of adsorbed water, coordinated water, amines, aromatics, ligands, chloropropyltrimethoxysilane and an increase in thermal stability (removal of ligand) of silicas anchored [Ni(L1)]SBA-15, [Ni(L2)SBA-15 and [Ni(L3)SBA-15 compared of free complexes, showing successful anchoring of complex molecular sieve.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-08-09T22:44:46Z No. of bitstreams: 1 IriaAlmeidaLealBassan_TESE.pdf: 3143028 bytes, checksum: 970a070c1dc06ffd41a2333aff70d989 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-08-10T22:36:43Z (GMT) No. of bitstreams: 1 IriaAlmeidaLealBassan_TESE.pdf: 3143028 bytes, checksum: 970a070c1dc06ffd41a2333aff70d989 (MD5) / Made available in DSpace on 2016-08-10T22:36:43Z (GMT). No. of bitstreams: 1 IriaAlmeidaLealBassan_TESE.pdf: 3143028 bytes, checksum: 970a070c1dc06ffd41a2333aff70d989 (MD5) Previous issue date: 2015-11-20 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Os lubrificantes e cortes de destilados m?dios possuem, normalmente, grandes quantidades de n-parafinas que lhes confere valores de pontos de congelamento e de fluidez mais elevados. Nesse sentido, a remo??o de n-parafinas de cadeias longas de ?leos lubrificantes e do diesel ? essencial para se obter um produto com boas propriedades de fluxo a frio. O desenvolvimento de novos catalisadores que apresentem estabilidade t?rmica e atividade catal?tica frente ? rea??o de hidroisomeriza??o ainda ? um desafio. Sendo assim, silicoaluminofosfatos (SAPO) foram sintetizados por diferentes rotas. Utilizou-se, tamb?m, tratamento p?s-s?ntese para obten??o de estruturas h?bridas e realizou-se s?nteses com direcionadores (soft templates e hard templates) de estrutura mesoporosa. Os catalisadores foram impregnados com platina, pelo m?todo de impregna??o ?mida, para posterior avalia??o catal?tica frente ? rea??o de hidroisomeriza??o do n-hexadecano. Al?m dos SAPO, fosfatos de ni?bio (NbP) tamb?m foram impregnados com platina e avaliados na referida rea??o. Ap?s a impregna??o, esses catalisadores foram caracterizados por difra??o de Raios X (DRX), adsor??o de nitrog?nio, espectroscopia no infravermelho com piridina adsorvida (IV-PY), microscopia eletr?nica de varredura (MEV), microscopia eletr?nica de transmiss?o (MET) e resson?ncia magn?tica nuclear do 29Si (29Si-RMN). Os resultados de caracteriza??o por DRX mostraram que foi poss?vel a obten??o de SAPO mesoestruturados. No entanto, para as s?nteses com soft template houve colapso da estrutura ap?s a remo??o dos direcionadores org?nicos. Mesmo assim, esses catalisadores apresentaram atividade catal?tica. Foi poss?vel a obten??o de materiais h?bridos por meio das s?nteses do SAPO-11 realizadas com hard templates e tamb?m por meio de tratamentos p?s- s?ntese em amostras de SAPO-11. Ademais, os NbP apresentaram DRX caracter?sticos de materiais amorfos, com alta acidez e foram ativos na convers?o do n-hexadecano. / Lubricants and cutting middle distillates typically have large amounts of n-paraffins to increase its freezing point and fluidity. Accordingly, the removal of n-paraffins of long chain lubricants oils and diesel is essential to get a product with good cold flow properties. The development of new catalysts, which exhibit thermal stability and catalytic activity for the hydroisomerization reaction is still a challenge. Thus, silicoaluminophosphates (SAPO) were synthesized by different routes. Have been used also post-synthesis treatment for obtaining hybrid structures and others synthesis have been carried out with mesoporous template (soft and hard-template). Therefore, SAPO have been impregnated with H2PtCl6 solution by the incipient wetness method. Then assessments of catalytic activities in hydroisomerization and hydrocracking reactions of hexadecane have been held. Besides SAPO, niobium phosphate - NbP - were also impregnated with platinum and evaluated in the same reaction. After impregnation, these catalysts have been characterized by X-ray diffraction (XRD), nitrogen adsorption, infrared spectroscopy with adsorbed pyridine (IV-PY), scanning electron microscopy (SEM) and resonance nuclear magnetic 29Si (29Si-NMR). The characterization results by XRD have shown that it has been possible to obtain mesoporous SAPOs. However, for the syntheses with soft template there was collapse of the structure after removal of the organic template. Even so, these catalysts have been actives. It was possible to obtain hybrid materials through the synthesis of SAPO-11 made with hard templates and by means of post-synthesis treatments samples of SAPO-11. Moreover, NbP has shown characteristic XRD of amorphous materials, with high acidity and were active in the conversion of hexadecane.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / The mesoporous materials like MCM-41apresentam hexagonal arrangement of mesopores with pore diameter from 2 to 10 nm and high surface area. Due to these characteristics, these materials are considered promising as support for heterogeneous catalysts, devices for controlled drug release and absorption. In this work, were synthesized mesoporous materials like MCM-41 via two synthesis routes in order to correlate the synthetic route to the surface area, assess their influence on the structural and morphological properties, and their respective application as dye adsorbent textiles. For both synthesis routes were used as precursors of silica gel, sodium silicate, water and cetyltrimethylammonium chloride (CTMABr), as an agent-driver structure. In the first synthesis route the materials were obtained by hydrothermal method with different temperatures (ambient 70 ° C and 100 ° C) and aging times (2h, 2 4h, 48h and 72h), with pH adjustment and every 24 hours calcinations at 550 ° C/4h. In the second synthesis route, we adopted the aging temperature environment and different times of crystallization (, 24h, 48h and 72h), no pH adjustment of the reaction medium and calcinations was performed at 550 ° C/6h. The MCM-41 was analyzed by X-ray diffraction (XRD), thermogravimetric analysis (TG, DTA and DTG), and absorption spectroscopy in the infrared (IR) and nitrogen adsorption (BET method - Brunauer-Emmett-Teller). Through the analysis of XRD, TG, IR and nitrogen adsorption showed that the calcination conditions were promising agent for the removal of driver structure and the optimization of routes allowed for the synthesis of MCM-41 with a shorter time and temperature aging, expected in the literature. However, it was not possible to establish a relationship between time, temperature and aging structural ordering of MCM-41. In addition, the test results of the use of MCM-41 as an adsorbent textile dye showed a higher adsorption of the dye Orange-16, for not calcined sample as compared to calcined sample at room temperature, confirming the promising application in the treatment of waste textiles. / Os materiais Mesoporosos do tipo MCM-41apresentam arranjo hexagonal de Mesoporoso com diâmetro de poro entre 2 a 10 nm e elevada área superficial. Devido a essas características, estes materiais são considerados promissores como suporte para catalisadores heterogêneos, dispositivos pra liberação controlada de fármacos e adsorção. Neste trabalho, foram sintetizados os materiais Mesoporosos do tipo MCM-41 através de duas rotas de síntese com o objetivo de correlacionar à rota sintética com a área superficial, avaliar sua influência sobre as propriedades estruturais e morfológicas, e sua respectiva aplicação como adsorvente de corante têxtil. Para as duas rotas de síntese utilizaram- se como precursores a sílica gel, silicato de sódio, água e o cloreto de cetiltrimetilamônio (CTMABr), como agente direcionador de estrutura. Na primeira rota de síntese os materiais foram obtidos através do método hidrotérmico, com diferentes temperaturas (ambiente, 70°C e 100°C) e tempos de envelhecimento (2h, 24h, 48h e 72h), com ajuste de pH a cada 24h e calcinação a 550°C/4h. Na segunda rota de síntese, adotou-se a temperatura de envelhecimento ambiente e diferentes tempos de cristalização (, 24h, 48h e 72h), não houve ajuste do pH do meio reacional e a calcinação foi realizada a 550°C/6h. Os MCM-41 obtidos foram analisados por difração de raios-X (DRX), análise termogravimétrica (TG, DTA e DTG), espectroscopia de absorção na região do infravermelho (IV) e adsorção de nitrogênio (método BET Brunauer- Emmett-Teller). Através das analises de DRX, TG, IV e adsorção de nitrogênio verificou-se que as condições de calcinação foram promissoras para a remoção do agente direcionador de estrutura e que a otimização das rotas possibilitou a síntese de MCM- 41 com um menor tempo e temperatura de envelhecimento, que o previsto na literatura. Entretanto, não foi possível estabelecer uma relação entre o tempo, temperatura de envelhecimento e ordenação estruturald do MCM-41. Além disso, os resultados dos ensaios da utilização do MCM-41 como adsorvente de corante têxtil mostraram uma elevada adsorção do corante Orange-16, para amostra não calcinada quando comparada a amostra calcinada, a temperatura ambiente, confirmando a promissora aplicação no tratamento de resíduos têxteis.

Made available in DSpace on 2014-12-17T15:41:56Z (GMT). No. of bitstreams: 1 LidianeAM_DISSERT.pdf: 1970613 bytes, checksum: 036cbfe77378ec3746e57700b6ed691b (MD5) Previous issue date: 2012-01-30 / Volatile Organic Compounds are pollutants coming mainly from activities that use fossil fuels. Within this class are the BTEX (benzene, toluene, ethylbenzene and xylenes) compounds that are considered hazardous. Among the various existing techniques for degradation of pollutants, there is advanced oxidation using H2O2 generating hidoxil radical ( OH). In this work, the mesoporous material of MCM-41 was synthesized by hydrothermal method and then was used as support, the impregnation of titanium by the method of synthesis with excess solvent to obtain the catalyst Ti-MCM-41. The catalyst was used in the reaction catalyzed removal of BTEX in water using H2O2 as oxidant. The materials were characterized by: XRD, TG/DTG, FTIR, nitrogen adsorption-desorption and FRX-EDX, in order to verify the method of impregnation of the mesoporous titanium support was effective. Catalytic tests were carried out in reactors of 20 mL containing BTEX (100.0 μg/L), H2O2 (2.0 M) and Ti-MCM-41 (2.0 g/L) in acid medium. The reaction occurred for 5 h at 60 ?C and analysis were performed by gas chromatography with photoionization detector and static headspace sampler. The characterizations have proven the effectiveness of the synthesis method used and the incorporation of titanium lt in the support. The catalytic tests showed satisfactory results with conversion of more than 95 % for the studied compounds, where the catalyst 48% Ti-MCM-41 showed a higher removal efficiency of the compounds under study / Os Compostos Org?nicos Vol?teis s?o poluentes oriundos, principalmente, de atividades que utilizam combust?veis fosseis. Dentro desta classe encontram-se os BTEX (benzeno, tolueno, etilbenzeno e xilenos) que s?o compostos considerados perigosos. Dentre as varias t?cnicas existentes para degrada??o de poluentes, destaca-se a oxida??o avan?ada utilizando H2O2 para gera??o do radical hidoxil ( OH). Neste trabalho, o material mesoporoso do tipo MCM-41 foi sintetizado atrav?s do m?todo hidrot?rmica e em seguida foi utilizado como suporte, na impregna??o de tit?nio pelo m?todo p?s-s?ntese com excesso de solvente para a obten??o do catalisador Ti-MCM-41. O catalisador foi utilizado na cat?lise da rea??o de remo??o dos BTEX em meio aquoso utilizando H2O2 como oxidante. Os materiais obtidos foram caracterizados por: DRX, TG/DTG, FTIR, adsor??o/dessor??o de N2, FRX-EDX, com o objetivo de verificar se o m?todo de impregna??o do tit?nio no suporte mesoporoso foi eficiente. Os testes catal?ticos foram realizados em reatores de 20 mL contendo solu??o aquosa de BTEX (100,0 μg/L), H2O2 (0,1 M) e Ti-MCM-41 (2,0 g/L) em meio acido. A rea??o ocorreu por 5 h a 60 ?C e as analises foram feitas por cromatografia a g?s com detector de fotoionizacao e amostrador por headspace est?tico. As caracteriza??es comprovaram a efic?cia do m?todo de s?ntese utilizado, assim como a incorpora??o do tit?nio no suporte. Os testes catal?ticos apresentaram resultados satisfat?rios na remo??o de mais de 95 % para os compostos estudados, onde o catalisador 48% Ti-MCM-41 apresentou uma maior efici?ncia na remo??o dos compostos em estudo

Made available in DSpace on 2014-12-17T14:07:04Z (GMT). No. of bitstreams: 1 AndersonJS_DISSERT.pdf: 4871519 bytes, checksum: 507c2ee7d7475d1557abdee7e257a648 (MD5) Previous issue date: 2012-12-17 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The MCM-41 mesoporous synthesis was done using rice hulls ash and chrysotile as natural alternative silica sources. For the using of these sources, chemical and thermic treatments were done in both materials. After chemical and thermic treatments, these materials were employed on the MCM-41 mesoctructures synthesis. The natural materials treated and employed in the synthesis were characterized by several techniques such as X-ray diffraction, N2 adsorption and desorption, scanning electronic microscopy and thermogravimetric analysis. MCM-41 standart samples synthetized with aerosil 200 commercial s?lica were used to evaluation. The formed material from rice hulls ash showed values from BET specific area about 468 m?.g-1, N2 adsorption and desorption isotherms and loss mass similar to reference materials. The silica from chrysotile calcined and leached was employed to mesoporous materials synthesis. The BET specific area showed values about 700 m?.g-1, N2 adsorption and desorption isotherms type IV and loss mass similar to mesoporous materials. The formed material from calcined and leached chrysotile, without calcination, applied to phenol remotion carried high performance liquid chromatography and evaluated with organophilic clays with different treatments. By the characterization techniques were proved that mesoporous materials with lesser order that reference samples. The material formed from rice hulls ash without the calcination step achieved better adsorption results than organophilic clays / A s?ntese dos mesoporosos do tipo MCM-41 foram realizadas empregando materiais naturais como cinza da casca de arroz e crisotila como fontes alternativas de s?lica. Para a utiliza??o destas fontes, tratamentos t?rmicos e qu?micos foram realizados em ambos os materiais. Os materiais naturais, ap?s tratamento t?rmico e qu?mico, foram empregados na forma??o de mesoestruturas do tipo MCM-41. Os materiais naturais, tratados e empregados na s?ntese foram caracterizados por diversas t?cnicas, como difra??o de raios-X, adsor??o e dessor??o de N2, microscopia eletr?nica de varredura e an?lise termogravim?trica. Amostras padr?es de MCM-41 sintetizadas com s?lica comercial pirolisada aerosil 200 foram utilizadas como crit?rio de compara??o. O material formado a partir da cinza da casca de arroz calcinada e lixiviada apresentou ?rea espec?fica de 468 m?.g-1, isotermas de adsor??o e dessor??o de N2 t?picas de materiais mesoporosos e eventos de perda de massa semelhantes a amostra de refer?ncia. A s?lica derivada da crisotila calcinada e lixiviada foram utilizadas para a s?ntese de materiais mesoporosos. O material apresentou valores de ?rea espec?fica BET de 700 m?.g-1, isotermas de adsor??o e dessor??o de N2 do tipo IV e perdas de massa caracter?sticas de materiais mesoporosos. O material formado a partir da cinza da casca de arroz, sem a etapa de calcina??o foi aplicado na adsor??o de fenol acompanhado por cromatografia l?quida de alta efici?ncia (CLAE) e comparado com argilas organof?licas com diversos tratamentos. Pelas t?cnicas de caracteriza??o comprova-se que os materiais s?o do possuem menor ordena??o que a amostra de refer?ncia. O material formado a partir da cinza da casca de arroz, e sem a etapa de calcina??o, obteve melhores resultados de adsor??o de fenol, se comparado ?s argilas organof?licas