Síntese e caracterização de argilas pilarizadas com pilares mistos Al/Co
Autor(a) principal: | |
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Data de Publicação: | 2014 |
Tipo de documento: | Dissertação |
Idioma: | por |
Título da fonte: | Repositório Institucional da UFRN |
Texto Completo: | https://repositorio.ufrn.br/jspui/handle/123456789/17753 |
Resumo: | Two pillaring methods were tested to synthesize pillared clays containing mixed Al/Co pillars. Using the first method, based on the traditional procedure, were obtained materials containing different Co concentrations: 10, 25, 50, 75 and 100 % of Co in the pillaring solution. Just the experiments with low concentrations (10 and 25 % of Co) has formed pillared clays, whereas the sample with 25 % of cobalt showed best results compared with the one obtained just using Al as pillaring agent (basal spacing higher than 18 Å and surface area bigger than 300 m²/g). The 27Al NMR results pointed out the formation of mixed Al/Co pillars due to decreased between the intensities of AlVI/AlIV signals, indicating that the AlIV content decreased while Co content increased, suggesting the isomorphic substitution of Al atoms for Co in the Keggin ion structure (pillaring agent). For the samples containing 75 and 100 % of cobalt, it was verified the formation of others materials, which could be identified as hydrotalcite like compounds. The second pillarization method was named mixed layers, because the objective was to intercalate clay layers with hydrotalcite layers. Thus, after calcination, the hydrotalcite layers would dehydroxylate, resulting just in the metals oxides, intercalated between the clay sheets, thus generating, a pillared clay. For this purpose, were tested 4 synthesis procedures: physical mixture, mixture in water, ionic exchange under reflux and in situ synthesis. Of these, the method which showed the best results was the in situ synthesis, in which basal spacings of 14 Å (after calcination) were obtained, indicating that the samples are intercalated with metal oxides (Mg and Al). This procedure was reproduced with a Co-Al LDH (layered double hydroxide) and similar results were obtained, testifying the method reproducibility |
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Bertella, Francinehttp://lattes.cnpq.br/8014195249680638http://lattes.cnpq.br/5249001430287414Oliveira, Luiz Carlos Alves dehttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4795801A1Alcântara, Ana Clécia Santos dehttp://lattes.cnpq.br/3149929057352643Fernandes, Nedja Suelyhttp://lattes.cnpq.br/9563490368583906Pergher, Sibele Berenice Castella2014-12-17T15:42:15Z2014-09-052014-12-17T15:42:15Z2014-05-22BERTELLA, Francine. Clays. Pillaring. Al/Co mixed pillars. Layer double hydroxide. 2014. 131 f. Dissertação (Mestrado em Físico-Química; Química) - Universidade Federal do Rio Grande do Norte, Natal, 2014.https://repositorio.ufrn.br/jspui/handle/123456789/17753Two pillaring methods were tested to synthesize pillared clays containing mixed Al/Co pillars. Using the first method, based on the traditional procedure, were obtained materials containing different Co concentrations: 10, 25, 50, 75 and 100 % of Co in the pillaring solution. Just the experiments with low concentrations (10 and 25 % of Co) has formed pillared clays, whereas the sample with 25 % of cobalt showed best results compared with the one obtained just using Al as pillaring agent (basal spacing higher than 18 Å and surface area bigger than 300 m²/g). The 27Al NMR results pointed out the formation of mixed Al/Co pillars due to decreased between the intensities of AlVI/AlIV signals, indicating that the AlIV content decreased while Co content increased, suggesting the isomorphic substitution of Al atoms for Co in the Keggin ion structure (pillaring agent). For the samples containing 75 and 100 % of cobalt, it was verified the formation of others materials, which could be identified as hydrotalcite like compounds. The second pillarization method was named mixed layers, because the objective was to intercalate clay layers with hydrotalcite layers. Thus, after calcination, the hydrotalcite layers would dehydroxylate, resulting just in the metals oxides, intercalated between the clay sheets, thus generating, a pillared clay. For this purpose, were tested 4 synthesis procedures: physical mixture, mixture in water, ionic exchange under reflux and in situ synthesis. Of these, the method which showed the best results was the in situ synthesis, in which basal spacings of 14 Å (after calcination) were obtained, indicating that the samples are intercalated with metal oxides (Mg and Al). This procedure was reproduced with a Co-Al LDH (layered double hydroxide) and similar results were obtained, testifying the method reproducibilityDois métodos de pilarização de argilas foram testados a fim de se obter argilas pilarizadas com pilares mistos Al/Co. Utilizando o primeiro método, baseado no procedimento tradicional, foram obtidos materiais contendo diferentes teores de Co: 10, 25, 50, 75 e 100 % de Co na solução pilarizante. Apenas os métodos contendo baixos teores (10 e 25 % de Co) resultaram na formação de argilas pilarizadas, sendo que, a amostra contendo 25 % de cobalto apresentou resultados superiores aos obtidos apenas com Al (espaçamento basal acima de 18 Å e área específica BET maior que 300 m²/g). Os resultados de RMN de 27Al indicaram a formação de pilares mistos Al/Co devido à diminuição entre as intensidades dos sinais AlVI/AlIV, indicando que o teor de AlVI diminuiu conforme ocorreu o aumento do teor de Co, sugerindo a substituição isomórfica de átomos de Al por Co na estrutura do íon de Keggin (agente pilarizante). Para as amostras contendo 75 e 100 % de cobalto, verificou-se a formação de outros materiais, os quais foram identificados como sendo compostos do tipo hidrotalcita. O segundo método de pilarização foi chamado de lamelas mistas, pois o objetivo era intercalar lamelas de argila com lamelas de hidrotalcita, assim após a calcinação, ocorreria a desidroxilação da camada de HDL (hidróxido duplo lamelar), resultando apenas nos óxidos de metais, intercalados entre as lamelas da argila, gerando uma argila pilarizada. Para tal, foram testados 4 procedimentos de síntese: mistura física, mistura em água, troca iônica em refluxo e síntese in situ. Desses, o método que apresentou os resultados mais promissores foi o de síntese in situ, no qual espaçamentos da ordem de 14 Å (após calcinar) foram obtidos, indicando que as amostras estão intercaladas com óxidos de metais (Mg e Al). Esse procedimento foi reproduzido com uma HDL contendo Co-Al, e resultados semelhantes foram obtidos, comprovando a reprodutibilidade do métodoConselho Nacional de Desenvolvimento Científico e Tecnológicoapplication/pdfporUniversidade Federal do Rio Grande do NortePrograma de Pós-Graduação em QuímicaUFRNBRFísico-Química; QuímicaArgilas. Pilarização. Pilares mistos Al/Co. Hidróxido duplo lamelarCNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICASíntese e caracterização de argilas pilarizadas com pilares mistos Al/CoClays. Pillaring. Al/Co mixed pillars. Layer double hydroxideinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFRNinstname:Universidade Federal do Rio Grande do Norte (UFRN)instacron:UFRNORIGINALFrancineB_DISSERT.pdfapplication/pdf3873354https://repositorio.ufrn.br/bitstream/123456789/17753/1/FrancineB_DISSERT.pdf665d87a2180d2517b91bf821d327dc87MD51TEXTFrancineB_DISSERT.pdf.txtFrancineB_DISSERT.pdf.txtExtracted texttext/plain218498https://repositorio.ufrn.br/bitstream/123456789/17753/6/FrancineB_DISSERT.pdf.txt983770ecf245bea5eb8a0666d389a26fMD56THUMBNAILFrancineB_DISSERT.pdf.jpgFrancineB_DISSERT.pdf.jpgIM Thumbnailimage/jpeg5264https://repositorio.ufrn.br/bitstream/123456789/17753/7/FrancineB_DISSERT.pdf.jpgc25e35a6ce0b4c509619e825bfbf1d65MD57123456789/177532017-11-04 14:28:08.936oai:https://repositorio.ufrn.br:123456789/17753Repositório de PublicaçõesPUBhttp://repositorio.ufrn.br/oai/opendoar:2017-11-04T17:28:08Repositório Institucional da UFRN - Universidade Federal do Rio Grande do Norte (UFRN)false |
dc.title.por.fl_str_mv |
Síntese e caracterização de argilas pilarizadas com pilares mistos Al/Co |
dc.title.alternative.eng.fl_str_mv |
Clays. Pillaring. Al/Co mixed pillars. Layer double hydroxide |
title |
Síntese e caracterização de argilas pilarizadas com pilares mistos Al/Co |
spellingShingle |
Síntese e caracterização de argilas pilarizadas com pilares mistos Al/Co Bertella, Francine Argilas. Pilarização. Pilares mistos Al/Co. Hidróxido duplo lamelar CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
title_short |
Síntese e caracterização de argilas pilarizadas com pilares mistos Al/Co |
title_full |
Síntese e caracterização de argilas pilarizadas com pilares mistos Al/Co |
title_fullStr |
Síntese e caracterização de argilas pilarizadas com pilares mistos Al/Co |
title_full_unstemmed |
Síntese e caracterização de argilas pilarizadas com pilares mistos Al/Co |
title_sort |
Síntese e caracterização de argilas pilarizadas com pilares mistos Al/Co |
author |
Bertella, Francine |
author_facet |
Bertella, Francine |
author_role |
author |
dc.contributor.authorID.por.fl_str_mv |
|
dc.contributor.authorLattes.por.fl_str_mv |
http://lattes.cnpq.br/8014195249680638 |
dc.contributor.advisorID.por.fl_str_mv |
|
dc.contributor.advisorLattes.por.fl_str_mv |
http://lattes.cnpq.br/5249001430287414 |
dc.contributor.referees1.pt_BR.fl_str_mv |
Oliveira, Luiz Carlos Alves de |
dc.contributor.referees1ID.por.fl_str_mv |
|
dc.contributor.referees1Lattes.por.fl_str_mv |
http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4795801A1 |
dc.contributor.referees2.pt_BR.fl_str_mv |
Alcântara, Ana Clécia Santos de |
dc.contributor.referees2ID.por.fl_str_mv |
|
dc.contributor.referees2Lattes.por.fl_str_mv |
http://lattes.cnpq.br/3149929057352643 |
dc.contributor.referees3.pt_BR.fl_str_mv |
Fernandes, Nedja Suely |
dc.contributor.referees3ID.por.fl_str_mv |
|
dc.contributor.referees3Lattes.por.fl_str_mv |
http://lattes.cnpq.br/9563490368583906 |
dc.contributor.author.fl_str_mv |
Bertella, Francine |
dc.contributor.advisor1.fl_str_mv |
Pergher, Sibele Berenice Castella |
contributor_str_mv |
Pergher, Sibele Berenice Castella |
dc.subject.por.fl_str_mv |
Argilas. Pilarização. Pilares mistos Al/Co. Hidróxido duplo lamelar |
topic |
Argilas. Pilarização. Pilares mistos Al/Co. Hidróxido duplo lamelar CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
dc.subject.cnpq.fl_str_mv |
CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
description |
Two pillaring methods were tested to synthesize pillared clays containing mixed Al/Co pillars. Using the first method, based on the traditional procedure, were obtained materials containing different Co concentrations: 10, 25, 50, 75 and 100 % of Co in the pillaring solution. Just the experiments with low concentrations (10 and 25 % of Co) has formed pillared clays, whereas the sample with 25 % of cobalt showed best results compared with the one obtained just using Al as pillaring agent (basal spacing higher than 18 Å and surface area bigger than 300 m²/g). The 27Al NMR results pointed out the formation of mixed Al/Co pillars due to decreased between the intensities of AlVI/AlIV signals, indicating that the AlIV content decreased while Co content increased, suggesting the isomorphic substitution of Al atoms for Co in the Keggin ion structure (pillaring agent). For the samples containing 75 and 100 % of cobalt, it was verified the formation of others materials, which could be identified as hydrotalcite like compounds. The second pillarization method was named mixed layers, because the objective was to intercalate clay layers with hydrotalcite layers. Thus, after calcination, the hydrotalcite layers would dehydroxylate, resulting just in the metals oxides, intercalated between the clay sheets, thus generating, a pillared clay. For this purpose, were tested 4 synthesis procedures: physical mixture, mixture in water, ionic exchange under reflux and in situ synthesis. Of these, the method which showed the best results was the in situ synthesis, in which basal spacings of 14 Å (after calcination) were obtained, indicating that the samples are intercalated with metal oxides (Mg and Al). This procedure was reproduced with a Co-Al LDH (layered double hydroxide) and similar results were obtained, testifying the method reproducibility |
publishDate |
2014 |
dc.date.accessioned.fl_str_mv |
2014-12-17T15:42:15Z |
dc.date.available.fl_str_mv |
2014-09-05 2014-12-17T15:42:15Z |
dc.date.issued.fl_str_mv |
2014-05-22 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.citation.fl_str_mv |
BERTELLA, Francine. Clays. Pillaring. Al/Co mixed pillars. Layer double hydroxide. 2014. 131 f. Dissertação (Mestrado em Físico-Química; Química) - Universidade Federal do Rio Grande do Norte, Natal, 2014. |
dc.identifier.uri.fl_str_mv |
https://repositorio.ufrn.br/jspui/handle/123456789/17753 |
identifier_str_mv |
BERTELLA, Francine. Clays. Pillaring. Al/Co mixed pillars. Layer double hydroxide. 2014. 131 f. Dissertação (Mestrado em Físico-Química; Química) - Universidade Federal do Rio Grande do Norte, Natal, 2014. |
url |
https://repositorio.ufrn.br/jspui/handle/123456789/17753 |
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por |
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por |
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info:eu-repo/semantics/openAccess |
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openAccess |
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Universidade Federal do Rio Grande do Norte |
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Programa de Pós-Graduação em Química |
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UFRN |
dc.publisher.country.fl_str_mv |
BR |
dc.publisher.department.fl_str_mv |
Físico-Química; Química |
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Universidade Federal do Rio Grande do Norte |
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