Positron studies of the temperature-dependence of free volumes in Polydimethylsiloxane/poly(propylene oxide) urethane/urea membranes

Detalhes bibliográficos
Autor(a) principal: Marques, M. F. Ferreira
Data de Publicação: 2007
Outros Autores: Gordo, P. M., Kajcsos, Zs., Gil, C. Lopes, Lima, A. P. de, Queiroz, D. P., Pinho, M. N. de
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Texto Completo: http://hdl.handle.net/10316/4385
https://doi.org/10.1016/j.radphyschem.2006.03.017
Resumo: Free-volume parameters in polyurethane/urea membranes have been studied by positron annihilation lifetime and Doppler broadening measurements. The bi-soft segment membranes were obtained by varying the ratio of the structural constituents, polypropylene oxide and polydimethylsiloxane (PU/PDMS), with PDMS content from 25 to 75 wt%. The free-volume holes determined by PALS are correlated with gas permeation features. The phase separation of the various soft and hard segments in the membranes is mirrored in both lifetime and Doppler results.
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spelling Positron studies of the temperature-dependence of free volumes in Polydimethylsiloxane/poly(propylene oxide) urethane/urea membranesPositroniumMembranesPhase separationPermeabilityDoppler broadeningLifetimeFree-volumeFree-volume parameters in polyurethane/urea membranes have been studied by positron annihilation lifetime and Doppler broadening measurements. The bi-soft segment membranes were obtained by varying the ratio of the structural constituents, polypropylene oxide and polydimethylsiloxane (PU/PDMS), with PDMS content from 25 to 75 wt%. The free-volume holes determined by PALS are correlated with gas permeation features. The phase separation of the various soft and hard segments in the membranes is mirrored in both lifetime and Doppler results.http://www.sciencedirect.com/science/article/B6TVT-4JW121G-1/1/59e25db8fec6b7e1914d12ccdb82ade22007info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleaplication/PDFhttp://hdl.handle.net/10316/4385http://hdl.handle.net/10316/4385https://doi.org/10.1016/j.radphyschem.2006.03.017engRadiation Physics and Chemistry. 76:2 (2007) 129-133Marques, M. F. FerreiraGordo, P. M.Kajcsos, Zs.Gil, C. LopesLima, A. P. deQueiroz, D. P.Pinho, M. N. deinfo: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:RCAAP2021-10-12T10:59:04Zoai:estudogeral.uc.pt:10316/4385Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T20:59:35.637450Repositório 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 Positron studies of the temperature-dependence of free volumes in Polydimethylsiloxane/poly(propylene oxide) urethane/urea membranes
title Positron studies of the temperature-dependence of free volumes in Polydimethylsiloxane/poly(propylene oxide) urethane/urea membranes
spellingShingle Positron studies of the temperature-dependence of free volumes in Polydimethylsiloxane/poly(propylene oxide) urethane/urea membranes
Marques, M. F. Ferreira
Positronium
Membranes
Phase separation
Permeability
Doppler broadening
Lifetime
Free-volume
title_short Positron studies of the temperature-dependence of free volumes in Polydimethylsiloxane/poly(propylene oxide) urethane/urea membranes
title_full Positron studies of the temperature-dependence of free volumes in Polydimethylsiloxane/poly(propylene oxide) urethane/urea membranes
title_fullStr Positron studies of the temperature-dependence of free volumes in Polydimethylsiloxane/poly(propylene oxide) urethane/urea membranes
title_full_unstemmed Positron studies of the temperature-dependence of free volumes in Polydimethylsiloxane/poly(propylene oxide) urethane/urea membranes
title_sort Positron studies of the temperature-dependence of free volumes in Polydimethylsiloxane/poly(propylene oxide) urethane/urea membranes
author Marques, M. F. Ferreira
author_facet Marques, M. F. Ferreira
Gordo, P. M.
Kajcsos, Zs.
Gil, C. Lopes
Lima, A. P. de
Queiroz, D. P.
Pinho, M. N. de
author_role author
author2 Gordo, P. M.
Kajcsos, Zs.
Gil, C. Lopes
Lima, A. P. de
Queiroz, D. P.
Pinho, M. N. de
author2_role author
author
author
author
author
author
dc.contributor.author.fl_str_mv Marques, M. F. Ferreira
Gordo, P. M.
Kajcsos, Zs.
Gil, C. Lopes
Lima, A. P. de
Queiroz, D. P.
Pinho, M. N. de
dc.subject.por.fl_str_mv Positronium
Membranes
Phase separation
Permeability
Doppler broadening
Lifetime
Free-volume
topic Positronium
Membranes
Phase separation
Permeability
Doppler broadening
Lifetime
Free-volume
description Free-volume parameters in polyurethane/urea membranes have been studied by positron annihilation lifetime and Doppler broadening measurements. The bi-soft segment membranes were obtained by varying the ratio of the structural constituents, polypropylene oxide and polydimethylsiloxane (PU/PDMS), with PDMS content from 25 to 75 wt%. The free-volume holes determined by PALS are correlated with gas permeation features. The phase separation of the various soft and hard segments in the membranes is mirrored in both lifetime and Doppler results.
publishDate 2007
dc.date.none.fl_str_mv 2007
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/10316/4385
http://hdl.handle.net/10316/4385
https://doi.org/10.1016/j.radphyschem.2006.03.017
url http://hdl.handle.net/10316/4385
https://doi.org/10.1016/j.radphyschem.2006.03.017
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv Radiation Physics and Chemistry. 76:2 (2007) 129-133
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv aplication/PDF
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
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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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