Structure and photoluminescent features of di-amide cross-linked alkylene-siloxane hybrids
Autor(a) principal: | |
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Data de Publicação: | 2005 |
Outros Autores: | , , , , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/1822/5482 |
Resumo: | Novel amide cross-linked alkylene/siloxane hybrid materials (di-amidosils) synthesized by the sol-gel process have been investigated. Two samples identified by the notation d-A(x) with x = 4 and 8 (where x is the number of methylene groups of the alkylene chain) have been produced as transparent, amorphous, rigid monoliths, thermally stable up to about 381 and 400 ºC, respectively. In the d-A(8) hybrid the siliceous framework is composed of [(SiO)3Si(CH2)-] and [(SiO)2(HO)Si(CH2)-] substructures. Structural unit distances of 4.1 and 4.2 Å and average interparticle distances of 12 and 17 Å have been determined for d-A(4) and d-A(8), respectively. In these compounds the alkyl chains are disordered and adopt gauche conformations. While a negligible proportion of the amide linkages remain non-bonded, the great majority of these groups belong to highly disordered strong hydrogen-bonded amide-amide associations. The hybrids introduced are room temperature white light emitters, presenting an emission large, broad band in the blue/purplish-blue spectral region. The origin of such band have been ascribed to the convolution of donor-acceptor pair (D-A) recombinations that occur in the NH groups of the urea linkages and in the siliceous nanodomains. The maximum quantum yield value of the d-A(8) di-amidosil is 5.4 %. |
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Structure and photoluminescent features of di-amide cross-linked alkylene-siloxane hybridsSol-gel synthesisThermal stabilityScience & TechnologyNovel amide cross-linked alkylene/siloxane hybrid materials (di-amidosils) synthesized by the sol-gel process have been investigated. Two samples identified by the notation d-A(x) with x = 4 and 8 (where x is the number of methylene groups of the alkylene chain) have been produced as transparent, amorphous, rigid monoliths, thermally stable up to about 381 and 400 ºC, respectively. In the d-A(8) hybrid the siliceous framework is composed of [(SiO)3Si(CH2)-] and [(SiO)2(HO)Si(CH2)-] substructures. Structural unit distances of 4.1 and 4.2 Å and average interparticle distances of 12 and 17 Å have been determined for d-A(4) and d-A(8), respectively. In these compounds the alkyl chains are disordered and adopt gauche conformations. While a negligible proportion of the amide linkages remain non-bonded, the great majority of these groups belong to highly disordered strong hydrogen-bonded amide-amide associations. The hybrids introduced are room temperature white light emitters, presenting an emission large, broad band in the blue/purplish-blue spectral region. The origin of such band have been ascribed to the convolution of donor-acceptor pair (D-A) recombinations that occur in the NH groups of the urea linkages and in the siliceous nanodomains. The maximum quantum yield value of the d-A(8) di-amidosil is 5.4 %.Fundação para a Ciência e a Tecnologia (FCT) - POCTI/P/CTM/46780/03; SFRH/BD/13559/03.Royal Society of ChemistryUniversidade do MinhoNunes, SílviaZea Bermudez, V. deCybinska, J.Ferreira, R. A. SáCarlos, LuísSilva, Maria ManuelaSmith, Michael JohnOstrovskii, DavidRocha, João20052005-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/1822/5482eng"Journal of Materials Chemistry". ISSN 0959-9428. 15:35/36 (2005) 3876-3886.0959-942810.1039/b505372mhttp://www.rsc.org/ej/JM/2005/b505372m.pdfinfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-07-21T12:32:48Zoai:repositorium.sdum.uminho.pt:1822/5482Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T19:28:12.510657Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Structure and photoluminescent features of di-amide cross-linked alkylene-siloxane hybrids |
title |
Structure and photoluminescent features of di-amide cross-linked alkylene-siloxane hybrids |
spellingShingle |
Structure and photoluminescent features of di-amide cross-linked alkylene-siloxane hybrids Nunes, Sílvia Sol-gel synthesis Thermal stability Science & Technology |
title_short |
Structure and photoluminescent features of di-amide cross-linked alkylene-siloxane hybrids |
title_full |
Structure and photoluminescent features of di-amide cross-linked alkylene-siloxane hybrids |
title_fullStr |
Structure and photoluminescent features of di-amide cross-linked alkylene-siloxane hybrids |
title_full_unstemmed |
Structure and photoluminescent features of di-amide cross-linked alkylene-siloxane hybrids |
title_sort |
Structure and photoluminescent features of di-amide cross-linked alkylene-siloxane hybrids |
author |
Nunes, Sílvia |
author_facet |
Nunes, Sílvia Zea Bermudez, V. de Cybinska, J. Ferreira, R. A. Sá Carlos, Luís Silva, Maria Manuela Smith, Michael John Ostrovskii, David Rocha, João |
author_role |
author |
author2 |
Zea Bermudez, V. de Cybinska, J. Ferreira, R. A. Sá Carlos, Luís Silva, Maria Manuela Smith, Michael John Ostrovskii, David Rocha, João |
author2_role |
author author author author author author author author |
dc.contributor.none.fl_str_mv |
Universidade do Minho |
dc.contributor.author.fl_str_mv |
Nunes, Sílvia Zea Bermudez, V. de Cybinska, J. Ferreira, R. A. Sá Carlos, Luís Silva, Maria Manuela Smith, Michael John Ostrovskii, David Rocha, João |
dc.subject.por.fl_str_mv |
Sol-gel synthesis Thermal stability Science & Technology |
topic |
Sol-gel synthesis Thermal stability Science & Technology |
description |
Novel amide cross-linked alkylene/siloxane hybrid materials (di-amidosils) synthesized by the sol-gel process have been investigated. Two samples identified by the notation d-A(x) with x = 4 and 8 (where x is the number of methylene groups of the alkylene chain) have been produced as transparent, amorphous, rigid monoliths, thermally stable up to about 381 and 400 ºC, respectively. In the d-A(8) hybrid the siliceous framework is composed of [(SiO)3Si(CH2)-] and [(SiO)2(HO)Si(CH2)-] substructures. Structural unit distances of 4.1 and 4.2 Å and average interparticle distances of 12 and 17 Å have been determined for d-A(4) and d-A(8), respectively. In these compounds the alkyl chains are disordered and adopt gauche conformations. While a negligible proportion of the amide linkages remain non-bonded, the great majority of these groups belong to highly disordered strong hydrogen-bonded amide-amide associations. The hybrids introduced are room temperature white light emitters, presenting an emission large, broad band in the blue/purplish-blue spectral region. The origin of such band have been ascribed to the convolution of donor-acceptor pair (D-A) recombinations that occur in the NH groups of the urea linkages and in the siliceous nanodomains. The maximum quantum yield value of the d-A(8) di-amidosil is 5.4 %. |
publishDate |
2005 |
dc.date.none.fl_str_mv |
2005 2005-01-01T00:00:00Z |
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.uri.fl_str_mv |
http://hdl.handle.net/1822/5482 |
url |
http://hdl.handle.net/1822/5482 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
"Journal of Materials Chemistry". ISSN 0959-9428. 15:35/36 (2005) 3876-3886. 0959-9428 10.1039/b505372m http://www.rsc.org/ej/JM/2005/b505372m.pdf |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Royal Society of Chemistry |
publisher.none.fl_str_mv |
Royal Society of Chemistry |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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1799132776634515456 |