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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

S?ntese de silicogermanatos zeol?ticos empregando compostos am?nio quatern?rios como direcionadores de estrutura

Bieseki, Lindiane 17 June 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-02-17T18:43:03Z No. of bitstreams: 1 LindianeBieseki_TESE.pdf: 5268310 bytes, checksum: 259162ecc5d58cc1ee42eb6746ffdb22 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-02-17T20:42:31Z (GMT) No. of bitstreams: 1 LindianeBieseki_TESE.pdf: 5268310 bytes, checksum: 259162ecc5d58cc1ee42eb6746ffdb22 (MD5) / Made available in DSpace on 2017-02-17T20:42:31Z (GMT). No. of bitstreams: 1 LindianeBieseki_TESE.pdf: 5268310 bytes, checksum: 259162ecc5d58cc1ee42eb6746ffdb22 (MD5) Previous issue date: 2016-06-17 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / As ze?litas s?o uma classe de peneiras moleculares de estrutura cristalina e podem apresentar diferentes composi??es pela substitui??o de Si por outro elemento. No caso dos silicogermanatos, ?tomos de Si s?o substitu?dos por Ge na rede estrutural e s?o classificados como zeotipos. Neste estudo s?o apresentados resultados referentes a s?ntese de silicogermanatos zeol?ticos utilizando tr?s diferentes estrat?gias. Uma destas, ? a utiliza??o de compostos org?nicos que possam atuar como direcionadores de estrutura. No presente estudo foram utilizados 3 compostos diferentes com rela??o C/N+ de 6, 15 e 13, sendo dois compostos de uso in?dito em s?ntese de ze?litas. Os compostos foram avaliados em rela??o a resist?ncia a troca i?nica e em s?ntese de ze?litas utilizando diferentes composi??es, que incluem principalmente o uso de Sil?cio e Germ?nio e alguns testes com Boro. Algumas s?nteses foram realizadas em meio b?sico e outras em meio fluor?drico. Para caracteriza??o dos compostos org?nicos foram usadas as t?cnicas de Resson?ncia Magn?tica Nuclear (RMN), Espectroscopia na regi?o do Infravermelho (IV) e An?lise Qu?mica por CHN. Tamb?m foram realizados experimentos combinado o uso de um direcionador org?nico e um inorg?nico, neste caso LiOH. Os produtos de s?ntese de ze?litas foram caracterizados por Difra??o de raios-X (DRX), An?lise Termogravim?trica (TG), An?lise Qu?mica por CHN, an?lise qu?mica por Espectrometria de Emiss?o At?mica por Plasma Acoplado Indutivamente (ICP-AES), Espectroscopia na regi?o do Infravermelho (IV), Microscopia Eletr?nica de Varredura (MEV) e An?lise Qu?mica por Espectroscopia por Dispers?o de Energia (EDS). Com o uso do composto Iodeto de N,N,N-trimetil-2-adamantam?nio ? (3SDA(I)1), j? utilizado em s?ntese de ze?litas, foi sintetizado um silicogermanato com estrutura do tipo STT. / Zeolites are one class of molecular sieves with cristalline structure and may have different compositions for the replacement of Si by another element. In the case of silicogermanates, Si atoms were replaced by Ge in the structural network and are denominated zeotypes. In this study, results were obtained of the silicogermanate zeolites synthesis using different strategies. One of these is the use of organic compounds that can act as structure direct agent. In the present study, it was used three different compounds with C/N+ = 6, 15 and 13; being two of these novel compounds for use in zeolite synthesis. The compounds were evaluated for resistance to ion exchange and in zeolites synthesis using different compositions that primarily include the use of silicon and germanium and boron in some tests. Some syntheses were carried out in basic medium and others in the hydrofluoric medium. For characterization of organic compounds were used the Nuclear Magnetic Resonance techniques (NMR), Infrared spectroscopy (IR) and chemical analysis for CHN. Some procedures were also performed with the combined use of an organic and an inorganic driver, in this case LiOH. The zeolites synthesis products were characterized by Diffraction X-ray (XRD), Thermogravimetry analysis (TGA), chemical analysis by CHN, chemical analysis by Inductively plasma atomic emission spectroscopy (ICP-AES), Infrared Spectroscopy (IR) and Scanning electron microscope (SEM) and Energy Dispersive Spectroscopy (EDS). With the use of the N,N,N-Trimethyl-2-adamantammonium iodide - (3SDA(I)1), known in zeolite synthesis, it was possible to synthesize a silicogermanate with STT type structure.

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