Sol-gel-derived potassium-based di-ureasils for "smart windows"
Autor(a) principal: | |
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Data de Publicação: | 2007 |
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/1822/7751 |
Resumo: | Sol-gel derived KCF3SO3-doped di-urea cross-linked poly(oxyethylene) (POE)/siloxane (di-ureasil) ormolytes with ∞ > n ≥ 1 (n is the number of oxyethylene units per K+ ion) have been analysed. Samples with n > 40 are thermally stable up to 310 ºC. At n ≥ 100, POE crystallites are present. At n = 5 a crystalline POE/KCF3SO3 complex with stoichiometry 1:1 is formed. In the xerogel with n =1 this complex coexists with free salt. The highest ionic conductivity is reached at n = 20. “Free” anions and weakly coordinated CF3SO3- ions appear to be the main charge carriers. The K+ ions interact with the urea carbonyl oxygen atoms at all salt concentrations. Complexation of the cations by POE occurs at n ≤ 20. In the latter composition range, contact ion pairs and higher ionic aggregates develop. The ormolytes were successfully used in the assembly of electrochromic devices (ECDs) that exhibit good electrochemical stability and demonstrate a memory effect. The ECD incorporating the ormolyte with n = 20 displays an average transmittance in the visible region of ca. 90% in the coloured state and of 85-95% in the bleached atate. The corresponding change in colour, evaluated on the basis of the Commission Internationale d/Eclairage (CIE) colour-coordinate system, is reversible: from yellow (0.38, 0.37) for the bleached state to blue (0.29, 0.29) for the coloured state. |
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Sol-gel-derived potassium-based di-ureasils for "smart windows"Sol-gelPotassium triflateElectrochromic devicesScience & TechnologySol-gel derived KCF3SO3-doped di-urea cross-linked poly(oxyethylene) (POE)/siloxane (di-ureasil) ormolytes with ∞ > n ≥ 1 (n is the number of oxyethylene units per K+ ion) have been analysed. Samples with n > 40 are thermally stable up to 310 ºC. At n ≥ 100, POE crystallites are present. At n = 5 a crystalline POE/KCF3SO3 complex with stoichiometry 1:1 is formed. In the xerogel with n =1 this complex coexists with free salt. The highest ionic conductivity is reached at n = 20. “Free” anions and weakly coordinated CF3SO3- ions appear to be the main charge carriers. The K+ ions interact with the urea carbonyl oxygen atoms at all salt concentrations. Complexation of the cations by POE occurs at n ≤ 20. In the latter composition range, contact ion pairs and higher ionic aggregates develop. The ormolytes were successfully used in the assembly of electrochromic devices (ECDs) that exhibit good electrochemical stability and demonstrate a memory effect. The ECD incorporating the ormolyte with n = 20 displays an average transmittance in the visible region of ca. 90% in the coloured state and of 85-95% in the bleached atate. The corresponding change in colour, evaluated on the basis of the Commission Internationale d/Eclairage (CIE) colour-coordinate system, is reversible: from yellow (0.38, 0.37) for the bleached state to blue (0.29, 0.29) for the coloured state.Fundação para a Ciência e Tecnologia (FCT)Royal Society of ChemistryUniversidade do MinhoNunes, SílviaZea Bermudez, V. deSilva, Maria ManuelaSmith, Michael JohnOstrovskii, DavidFerreira, Rute SáCarlos, LuísRocha, JoãoGonçalves, A. I.Fortunato, E.20072007-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/1822/7751eng"Journal of Materials Chemistry". ISSN 0959-9428. 17 (2007) 4239-4248.0959-942810.1039/b708905hwww.rsc.orginfo: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:RCAAP2023-07-21T12:40:22Zoai:repositorium.sdum.uminho.pt:1822/7751Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T19:37:08.677267Repositório 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 |
Sol-gel-derived potassium-based di-ureasils for "smart windows" |
title |
Sol-gel-derived potassium-based di-ureasils for "smart windows" |
spellingShingle |
Sol-gel-derived potassium-based di-ureasils for "smart windows" Nunes, Sílvia Sol-gel Potassium triflate Electrochromic devices Science & Technology |
title_short |
Sol-gel-derived potassium-based di-ureasils for "smart windows" |
title_full |
Sol-gel-derived potassium-based di-ureasils for "smart windows" |
title_fullStr |
Sol-gel-derived potassium-based di-ureasils for "smart windows" |
title_full_unstemmed |
Sol-gel-derived potassium-based di-ureasils for "smart windows" |
title_sort |
Sol-gel-derived potassium-based di-ureasils for "smart windows" |
author |
Nunes, Sílvia |
author_facet |
Nunes, Sílvia Zea Bermudez, V. de Silva, Maria Manuela Smith, Michael John Ostrovskii, David Ferreira, Rute Sá Carlos, Luís Rocha, João Gonçalves, A. I. Fortunato, E. |
author_role |
author |
author2 |
Zea Bermudez, V. de Silva, Maria Manuela Smith, Michael John Ostrovskii, David Ferreira, Rute Sá Carlos, Luís Rocha, João Gonçalves, A. I. Fortunato, E. |
author2_role |
author 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 Silva, Maria Manuela Smith, Michael John Ostrovskii, David Ferreira, Rute Sá Carlos, Luís Rocha, João Gonçalves, A. I. Fortunato, E. |
dc.subject.por.fl_str_mv |
Sol-gel Potassium triflate Electrochromic devices Science & Technology |
topic |
Sol-gel Potassium triflate Electrochromic devices Science & Technology |
description |
Sol-gel derived KCF3SO3-doped di-urea cross-linked poly(oxyethylene) (POE)/siloxane (di-ureasil) ormolytes with ∞ > n ≥ 1 (n is the number of oxyethylene units per K+ ion) have been analysed. Samples with n > 40 are thermally stable up to 310 ºC. At n ≥ 100, POE crystallites are present. At n = 5 a crystalline POE/KCF3SO3 complex with stoichiometry 1:1 is formed. In the xerogel with n =1 this complex coexists with free salt. The highest ionic conductivity is reached at n = 20. “Free” anions and weakly coordinated CF3SO3- ions appear to be the main charge carriers. The K+ ions interact with the urea carbonyl oxygen atoms at all salt concentrations. Complexation of the cations by POE occurs at n ≤ 20. In the latter composition range, contact ion pairs and higher ionic aggregates develop. The ormolytes were successfully used in the assembly of electrochromic devices (ECDs) that exhibit good electrochemical stability and demonstrate a memory effect. The ECD incorporating the ormolyte with n = 20 displays an average transmittance in the visible region of ca. 90% in the coloured state and of 85-95% in the bleached atate. The corresponding change in colour, evaluated on the basis of the Commission Internationale d/Eclairage (CIE) colour-coordinate system, is reversible: from yellow (0.38, 0.37) for the bleached state to blue (0.29, 0.29) for the coloured state. |
publishDate |
2007 |
dc.date.none.fl_str_mv |
2007 2007-01-01T00:00:00Z |
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/1822/7751 |
url |
http://hdl.handle.net/1822/7751 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
"Journal of Materials Chemistry". ISSN 0959-9428. 17 (2007) 4239-4248. 0959-9428 10.1039/b708905h www.rsc.org |
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 |
instname_str |
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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1799132903620214784 |