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Orientador: Carol Hollingworth Collins / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-07T20:37:42Z (GMT). No. of bitstreams: 1 Faria_AnizioMarciode_D.pdf: 2871302 bytes, checksum: 58d9a466b2a4724df83a92414de3d9a9 (MD5) Previous issue date: 2006 / Doutorado / Quimica Analitica / Doutor em Quimica

Orientador: Carol Hollingworth Collins / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-22T07:24:16Z (GMT). No. of bitstreams: 1 Silva_CarlaGrazieliAzevedoda_D.pdf: 4489958 bytes, checksum: f1c0299f6db7beed410c437dcdfc5886 (MD5) Previous issue date: 2013 / Resumo: Este trabalho apresenta o desenvolvimento de fases estacionárias (FE) para cromatografia líquida de alta eficiência em fase reversa (CLAE-FR) e cromatografia com fluido supercrítico (CFS) a partir da imobilização térmica de poli(metiloctadecilsiloxano) (PMODS) sobre suportes de sílicas metalizadas com zircônio e titânio. O processo de imobilização térmica do PMODS foi otimizado aplicando-se planejamento composto central. O polímero, os suportes e as fases estacionárias foram caracterizados por testes físicoquímicos e cromatográficos. As fases estacionárias Si(PMODS), Si-Zr(PMODS) e Si-Ti(PMODS) apresentaram os melhores resultados quando foi aplicada a temperatura de 120 °C por 16 horas. As melhores FE foram submetidas ao processo de capeamento. Estas FE mostraram eficiências entre 82.000 e 90.000 pratos m e boas separações com picos simétricos para compostos apolares e picos com simetria adequada, segundo parâmetros estabelecidos pela Farmacopéia Americana (United States Pharmacopeia), para compostos polares, avaliados pelos testes de Engelhardt, Tanaka, Neue, SRM 870 e pelo modelo dos parâmetros de solvatação utilizando CFS. A presença do óxido metálico no suporte resultou em FE com maior estabilidade química em condições drásticas de fase móvel (pH 1,7 e pH 10 a 50 °C), quando comparada com fases similares baseadas em sílica nua. A reação de capeamento melhorou a estabilidade química das FE e diminuiu o número de silanóis residuais. As FE Si-Zr(PMODS), Si-Ti(PMODS), Si-Zr(PMODS)ec e Si- Ti(PMODS)ec apresentam potencialidade na separação de fármacos psicoativos, filtros ultravioleta (UV), xantinas e hidrocarbonetos policíclicos aromáticos (HPA), utilizando CLAE e CFS. / Abstract: This work presents the development of stationary phases (SP) for high performance liquid chromatography in the reversed phase (RP-HPLC) and for supercritical fluid chromatography (SFC) prepared by the sorption and thermal immobilization of poly(methyloctadecylsiloxane) (PMODS) onto silica and metalized silica supports modified with zirconium and titanium. The immobilization process was optimized using central composite design for determination of the best conditions of time and temperature. The polymer, supports and stationary phases were characterized with physico-chemical and chromatographic tests. The stationary phases Si(PMODS), Si-Zr(PMODS) and Si-Ti(PMODS) presented the best results when a temperature of 120 °C for 16 hours was applied. The best SP were submitted to endcapping processes. These SP showed efficiencies between 82,000 and 90,000 plates m and good separations with symmetric peaks for apolar and polar compounds evaluated by the Engelhardt, Tanaka, Neue and SRM 870 tests and the solvation parameter model using supercritical fluid chromatography (SFC). The presence of metallic oxide on the supports resulted in stationary phases with better chemical stability under drastic conditions of mobile phase (pH 1.7 and pH 10 at 50 °C), when compared to similar stationary phases based on bare silica. The endcapping reaction improved the chemical stability. The SP Si-Zr(PMODS), Si- Ti(PMODS), Si-Zr(PMODS)ec e Si-Ti(PMODS)ec presented potentialities for the separation different pharmaceutical compounds used as psychotropic drugs, ultraviolet (UV) filters, xanthines, and polycyclic aromatic hydrocarbons (PAH), using separations in HPLC and SFC. / Doutorado / Quimica Analitica / Doutor em Ciências

Chimie organométallique résonne avec catalyse homogène, et chimie des surfaces avec catalyse hétérogène. Mais la frontière établie entre ces deux domaines est en réalité très mince. Leur rapprochement aboutit dans les années 1990 au développement d’une nouvelle science : la chimie organométallique de surface, qui souligne leur complémentarité. L’objectif de cette science, dans laquelle s’inscrit ce travail de thèse, est de créer des catalyseurs hétérogènes à partir de composés organométalliques. Notre objectif est d’apporter une contribution à la compréhension de la formation de nanoparticules de platine - métal incontournable en catalyse hétérogène - sur des supports de silice amorphe, et ce grâce à la chimie organométallique. Au cours de ce travail, une palette de catalyseurs Pt/SiO2 a été préparée à partir de trois précurseurs de platine : le composé classique H2PtIVCl6.xH2O et deux composés organométalliques PtII(η 4-C8H12)Cl2 et Pt0(η 2-C7H10)3 , et de trois supports : une silice commerciale (Davison), une silice mésoporeuse SBA-15 synthétisée au laboratoire et unesilice naturelle, la diatomite. De plus, l’étude du catalyseur de référence au platine « EuroPt-1 » a permis de développer une méthodologie de suivi operando par Spectroscopie Infrarouge à Transformée de Fourier par Réflexion Diffuse (DRIFTS) de l’adsorption du monoxyde de carbone (CO) sur les différents sites d’une nanoparticule de platine. En conclusion, les catalyseurs préparés à partir de Pt0(η 2-C7H10)3 s’avèrent être plus actifs qu’EuroPt-1 pour la réaction d’oxydation du CO, ce qui démontre le potentiel d’utilisation des composés organométalliques dans le domaine de la catalyse hétérogène. / Organometallic chemistry resonates with homogeneous catalysis, and surface chemistry with heterogeneous catalysis. But the frontier between these two fields is very thin. In the 90’s, these fields approached each other and led to the development of a new science: organometallic surface chemistry, which underlines their complementarity. The goal of this science, with which this work is associated, is to create heterogeneous catalysts from organometallic compounds. Our goal is to contribute to the understanding of platinum nanoparticle formation - platinum being an important metal in heterogeneous catalysis - onto amorphous silica supports, thanks to organometallic chemistry. During this work, various Pt/SiO2 catalysts were prepared fromthree platinum precursors: the classical one, H2PtIVCl6.xH2O and two organometallic compounds PtII(η 4-C8H12)Cl2 et Pt0(η2-C7H10)3, and involved three supports: a commercial silica (Davison), a mesoporous silica SBA-15 synthesized in the laboratory, and a natural silica, the diatomite. Moreover, the study of the standard platinum reference catalyst “EuroPt-1” lead to the development of a methodology of operando Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) of carbon monoxide (CO) adsorption on the different sites of a platinum nanoparticle. Catalysts prepared from Pt0(η 2-C7H10)3 are more active than EuroPt-1 for the CO oxidation reaction, and this work shows the potential of organometallic precursors in the domain of heterogeneous catalysis.