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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Uma interpretação microscopica para a analise sistematica de cations / A microscopical interpretation for systematic cations analysis

Dantas, Josivania Marisa 10 October 2006 (has links)
Orientador : Pedro Faria dos Santos Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-07T19:57:18Z (GMT). No. of bitstreams: 1 Dantas_JosivaniaMarisa_M.pdf: 785971 bytes, checksum: 956ebcdc7258f32b05a05a39e08b2596 (MD5) Previous issue date: 2006 / Resumo: A análise sistemática de cátions é uma prática comum nos laboratórios de Química Analítica tanto na análise qualitativa realizada no meio acadêmico quanto na indústria, na identificação dos mais diferentes tipos de amostras desconhecidas. Esta prática é fruto de um vasto conhecimento de química acumulado de décadas por inúmeros pesquisadores e cientistas que conheciam a reatividade de muitas classes de compostos orgânicos e inorgânicos, bem como a propriedade de muitos deles. Em termos de ilustrar os métodos básicos de separação e identificação de íons, esta análise atinge seu objetivo. Contudo, não se conhece até o presente, nenhum texto que discute os conceitos químicos envolvidos em cada uma das etapas de separação e identificação de cátions. Neste trabalho foi elaborado um material didático para ser utilizado por alunos das várias modalidades dos cursos de Química. Nele foram enfatizados os fundamentos, conceitos e teorias envolvidos em cada um dos métodos explorados na análise sistemática de cátions. A produção deste material complementar aos já existentes não implica, de forma alguma, substituir o material utilizado atualmente. Para isto é utilizada a mesma divisão em grupos de cátions, apresentada em livros de Química Analítica Qualitativa. O material didático elaborado foi aplicado nas aulas desta disciplina no Instituto de Química da Unicamp e os resultados foram coletados por meio de questionários, participação e observação nas aulas / Abstract: The systematic cations analysis is a common practice in analytical chemistry laboratory for undergraduate students and also at the industry, for identification of different kinds of unknown samples. This practice is a result of a vast knowledge in chemistry acumulated during decades by researchers and cientists who knew the reactivity of several classes of organic and inorganic compounds, as well as its properties. In order to show the basic methods of ions identification and separation, this systematic analysis attain the desired objective. However, it is not known so far any text that discuss the chemistry concepts that relates the stages of cations separation and identification. In this work a didactic material was elaborated for undergraduate students, emphasiting the fundaments, concepts and theories involved in each one of the methods of systematic cations analysis. This supplementary didactic material was created in order to improve the currently used material. The same division of cations groups presented in the qualitative analytical chemistry books was mantained. The elaborated didactic material was applied in classes of this subject at Chemistry Institute of Unicamp and the results were collected by means of questionnaires and also classes participation and observation / Mestrado / Quimica Analitica / Doutor em Quimica
2

Élaboration de nouveaux fluoroionophores et de supports chélatants en vue de l'amélioration de la caractérisation du fer dans les particules atmosphériques / Elaboration of new fluoroionophores and chelating supports in order to ameliorate the characterization of iron in atmospheric particles

Danjou, Pierre-Édouard 26 November 2012 (has links)
L'objet de ce travail est de fournir de nouveaux outils moléculaires pour la caractérisation physico-chimique des particules atmosphériques afin d'établir des liens entre leurs propriétés et leur toxicité pulmonaire. Nous nous sommes plus particulièrement intéressés à la détection, la quantification et le traçage du fer, élément majeur dans les particules industrielles du bassin dunkerquois. Pour ce faire, nous avons mis au point dans un premier temps, la synthèse rapide de nouvelles sondes fluorescentes par micro-ondes et ultrasons. L'étude des propriétés spectroscopiesde ces nouvelles sondes a été menée et a permis de mettre en avant un composé sélectif des ions ferriques en solution aqueuse non temponnée en présence d'autres ions métalliques. Dans un second temps, nous avons réalisé des supports solides contenant des entités chélatantes supramoléculaires ou bio-inspirées afin de séparer les traces de fer ferrique de matrices aqueuses complexes. / The aim of this work is to provide new molecular tools for the physico-chemical characterization of atmospheric particles in order to establish a link between their properties and their pulmonary toxicity. We particularly investigate the detection and quantification of iron, a major element in industrial particle of Dunkirk city, France. So, in a first hand, we have developed the efficient synthesis of new fluorescents chemosensors by ultrasounds and microwave irradiation. Then the study of these compounds was undertaken and has revealed a highly selective sensor of ferric iron in non-buffered aqueous solution in presence of other metallic cation. In the other hand, we have synthesized new solid supports which beard supramolecular chelatant or bio-inspired entities in order to separate iron traces from complex aqueous matrix.

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