Structural characterization of mullites synthesized by thermal decomposition of topaz
Autor(a) principal: | |
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Data de Publicação: | 2007 |
Outros Autores: | , , , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UnB |
Texto Completo: | http://repositorio.unb.br/handle/10482/27082 https://dx.doi.org/10.1590/S1516-14392007000100016 |
Resumo: | The structure of mullite obtained by thermal decomposition of topaz at 1340 °C and after additional thermal treatment at 1600 °C was characterized by 29Si and 27Al MAS NMR spectroscopy and x ray diffraction. No amorphous phase was detected by these techniques. The 29Si MAS NMR spectra of the mullite samples showed four resonance peaks at -81, -86, -90 and -94 ppm. The peak at -81 ppm corresponded to silicon near oxygen vacancies in the mullite structure. The peak at 86 ppm was related to a sillimanite-type site and was the major contribution, ranging from 42 to 50%. The two other peaks, at -90.0 ppm and -94 ppm, were interpreted as resulting from rearrangements of the sillimanite-type site by the replacement of AlO4 by SiO4 tetrahedra16. The 27Al MAS NMR data of the two samples exhibited three different peaks, two of which were attributed to tetrahedral sites at 40 -45 and 63 -67 ppm, while the third was assigned to an octahedral site at about -6 ppm. The ratio of tetrahedral to octahedral aluminum sites was found to depend on the temperature applied during the preparation of the mullite and was higher at 1600 °C. |
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Soares, Robson de MirandaSabioni, Antônio Claret SoaresResck, Inês SabioniFalcomer, Viviane Aparecida SilvaDias, José AlvesSilva, Naira Machado daMenezes, Sônia Maria Cabral deCosta, Geraldo Magela da2017-12-07T04:48:30Z2017-12-07T04:48:30Z2007-03SOARES, Robson de Miranda et al. Structural characterization of mullites synthesized by thermal decomposition of topaz. Materials Research, São Carlos, v. 10, n. 1, p. 75-78, jan./mar. 2007. DOI: https://doi.org/10.1590/S1516-14392007000100016. Disponível em: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392007000100016&lng=en&nrm=iso. Acesso em: 12 jan. 2021.http://repositorio.unb.br/handle/10482/27082https://dx.doi.org/10.1590/S1516-14392007000100016ABM, ABC, ABPolMaterials Research - All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License (CC BY NC 4.0). Fonte: https://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392007000100016&lng=en&tlng=en. Acesso em: 12 jan. 2021.info:eu-repo/semantics/openAccessStructural characterization of mullites synthesized by thermal decomposition of topazinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleMulitaTopázioRaio X - difraçãoThe structure of mullite obtained by thermal decomposition of topaz at 1340 °C and after additional thermal treatment at 1600 °C was characterized by 29Si and 27Al MAS NMR spectroscopy and x ray diffraction. No amorphous phase was detected by these techniques. The 29Si MAS NMR spectra of the mullite samples showed four resonance peaks at -81, -86, -90 and -94 ppm. The peak at -81 ppm corresponded to silicon near oxygen vacancies in the mullite structure. The peak at 86 ppm was related to a sillimanite-type site and was the major contribution, ranging from 42 to 50%. The two other peaks, at -90.0 ppm and -94 ppm, were interpreted as resulting from rearrangements of the sillimanite-type site by the replacement of AlO4 by SiO4 tetrahedra16. The 27Al MAS NMR data of the two samples exhibited three different peaks, two of which were attributed to tetrahedral sites at 40 -45 and 63 -67 ppm, while the third was assigned to an octahedral site at about -6 ppm. The ratio of tetrahedral to octahedral aluminum sites was found to depend on the temperature applied during the preparation of the mullite and was higher at 1600 °C.Instituto de Química (IQ)engreponame:Repositório Institucional da UnBinstname:Universidade de Brasília (UnB)instacron:UNBORIGINALARTIGO_StructuralCharacterizationMullites.pdfARTIGO_StructuralCharacterizationMullites.pdfapplication/pdf855447http://repositorio2.unb.br/jspui/bitstream/10482/27082/1/ARTIGO_StructuralCharacterizationMullites.pdf100f8b58cc4b1c848b1ed2ca475eaed8MD51open access10482/270822023-10-20 09:44:38.807open accessoai:repositorio2.unb.br:10482/27082Biblioteca Digital de Teses e DissertaçõesPUBhttps://repositorio.unb.br/oai/requestopendoar:2023-10-20T12:44:38Repositório Institucional da UnB - Universidade de Brasília (UnB)false |
dc.title.pt_BR.fl_str_mv |
Structural characterization of mullites synthesized by thermal decomposition of topaz |
title |
Structural characterization of mullites synthesized by thermal decomposition of topaz |
spellingShingle |
Structural characterization of mullites synthesized by thermal decomposition of topaz Soares, Robson de Miranda Mulita Topázio Raio X - difração |
title_short |
Structural characterization of mullites synthesized by thermal decomposition of topaz |
title_full |
Structural characterization of mullites synthesized by thermal decomposition of topaz |
title_fullStr |
Structural characterization of mullites synthesized by thermal decomposition of topaz |
title_full_unstemmed |
Structural characterization of mullites synthesized by thermal decomposition of topaz |
title_sort |
Structural characterization of mullites synthesized by thermal decomposition of topaz |
author |
Soares, Robson de Miranda |
author_facet |
Soares, Robson de Miranda Sabioni, Antônio Claret Soares Resck, Inês Sabioni Falcomer, Viviane Aparecida Silva Dias, José Alves Silva, Naira Machado da Menezes, Sônia Maria Cabral de Costa, Geraldo Magela da |
author_role |
author |
author2 |
Sabioni, Antônio Claret Soares Resck, Inês Sabioni Falcomer, Viviane Aparecida Silva Dias, José Alves Silva, Naira Machado da Menezes, Sônia Maria Cabral de Costa, Geraldo Magela da |
author2_role |
author author author author author author author |
dc.contributor.author.fl_str_mv |
Soares, Robson de Miranda Sabioni, Antônio Claret Soares Resck, Inês Sabioni Falcomer, Viviane Aparecida Silva Dias, José Alves Silva, Naira Machado da Menezes, Sônia Maria Cabral de Costa, Geraldo Magela da |
dc.subject.keyword.pt_BR.fl_str_mv |
Mulita Topázio Raio X - difração |
topic |
Mulita Topázio Raio X - difração |
description |
The structure of mullite obtained by thermal decomposition of topaz at 1340 °C and after additional thermal treatment at 1600 °C was characterized by 29Si and 27Al MAS NMR spectroscopy and x ray diffraction. No amorphous phase was detected by these techniques. The 29Si MAS NMR spectra of the mullite samples showed four resonance peaks at -81, -86, -90 and -94 ppm. The peak at -81 ppm corresponded to silicon near oxygen vacancies in the mullite structure. The peak at 86 ppm was related to a sillimanite-type site and was the major contribution, ranging from 42 to 50%. The two other peaks, at -90.0 ppm and -94 ppm, were interpreted as resulting from rearrangements of the sillimanite-type site by the replacement of AlO4 by SiO4 tetrahedra16. The 27Al MAS NMR data of the two samples exhibited three different peaks, two of which were attributed to tetrahedral sites at 40 -45 and 63 -67 ppm, while the third was assigned to an octahedral site at about -6 ppm. The ratio of tetrahedral to octahedral aluminum sites was found to depend on the temperature applied during the preparation of the mullite and was higher at 1600 °C. |
publishDate |
2007 |
dc.date.issued.fl_str_mv |
2007-03 |
dc.date.accessioned.fl_str_mv |
2017-12-07T04:48:30Z |
dc.date.available.fl_str_mv |
2017-12-07T04:48:30Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.citation.fl_str_mv |
SOARES, Robson de Miranda et al. Structural characterization of mullites synthesized by thermal decomposition of topaz. Materials Research, São Carlos, v. 10, n. 1, p. 75-78, jan./mar. 2007. DOI: https://doi.org/10.1590/S1516-14392007000100016. Disponível em: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392007000100016&lng=en&nrm=iso. Acesso em: 12 jan. 2021. |
dc.identifier.uri.fl_str_mv |
http://repositorio.unb.br/handle/10482/27082 |
dc.identifier.doi.pt_BR.fl_str_mv |
https://dx.doi.org/10.1590/S1516-14392007000100016 |
identifier_str_mv |
SOARES, Robson de Miranda et al. Structural characterization of mullites synthesized by thermal decomposition of topaz. Materials Research, São Carlos, v. 10, n. 1, p. 75-78, jan./mar. 2007. DOI: https://doi.org/10.1590/S1516-14392007000100016. Disponível em: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392007000100016&lng=en&nrm=iso. Acesso em: 12 jan. 2021. |
url |
http://repositorio.unb.br/handle/10482/27082 https://dx.doi.org/10.1590/S1516-14392007000100016 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.publisher.none.fl_str_mv |
ABM, ABC, ABPol |
publisher.none.fl_str_mv |
ABM, ABC, ABPol |
dc.source.none.fl_str_mv |
reponame:Repositório Institucional da UnB instname:Universidade de Brasília (UnB) instacron:UNB |
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Universidade de Brasília (UnB) |
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UNB |
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UNB |
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Repositório Institucional da UnB |
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Repositório Institucional da UnB |
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http://repositorio2.unb.br/jspui/bitstream/10482/27082/1/ARTIGO_StructuralCharacterizationMullites.pdf |
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