Aluminum polyphosphate gels structural evolution probed by NMR spectroscopy

Detalhes bibliográficos
Autor(a) principal: Galembeck,André
Data de Publicação: 2003
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Journal of the Brazilian Chemical Society (Online)
Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532003000600010
Resumo: The aim of this work was to investigate how the structure of aluminum polyphosphate gels change upon aging and drying. This is essential if one is interested in using a gel as a matrix to synthesize organic-inorganic hybrid materials. The liquid and solid samples were characterized by 27Al and 31P NMR spectroscopy. Larger polyphosphate chains make the main contribution to gel formation and the smaller units are expelled into the supernatant solution. Polyphosphate chains undergo hydrolysis and chain scission upon gelation. Samples aged in a moisture-rich environment turn into viscous liquids as a consequence of water uptake, followed by extensive hydrolysis. Samples exposed to low relative humidity environments dry yielding brittle samples in which larger chains are stable. Vacuum-dried samples still contain ca. 30%-weight water.
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spelling Aluminum polyphosphate gels structural evolution probed by NMR spectroscopypolyphosphate gels31P NMR27Al NMRaluminum polyphosphatesol-gelThe aim of this work was to investigate how the structure of aluminum polyphosphate gels change upon aging and drying. This is essential if one is interested in using a gel as a matrix to synthesize organic-inorganic hybrid materials. The liquid and solid samples were characterized by 27Al and 31P NMR spectroscopy. Larger polyphosphate chains make the main contribution to gel formation and the smaller units are expelled into the supernatant solution. Polyphosphate chains undergo hydrolysis and chain scission upon gelation. Samples aged in a moisture-rich environment turn into viscous liquids as a consequence of water uptake, followed by extensive hydrolysis. Samples exposed to low relative humidity environments dry yielding brittle samples in which larger chains are stable. Vacuum-dried samples still contain ca. 30%-weight water.Sociedade Brasileira de Química2003-12-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532003000600010Journal of the Brazilian Chemical Society v.14 n.6 2003reponame:Journal of the Brazilian Chemical Society (Online)instname:Sociedade Brasileira de Química (SBQ)instacron:SBQ10.1590/S0103-50532003000600010info:eu-repo/semantics/openAccessGalembeck,Andréeng2004-02-11T00:00:00Zoai:scielo:S0103-50532003000600010Revistahttp://jbcs.sbq.org.brONGhttps://old.scielo.br/oai/scielo-oai.php||office@jbcs.sbq.org.br1678-47900103-5053opendoar:2004-02-11T00:00Journal of the Brazilian Chemical Society (Online) - Sociedade Brasileira de Química (SBQ)false
dc.title.none.fl_str_mv Aluminum polyphosphate gels structural evolution probed by NMR spectroscopy
title Aluminum polyphosphate gels structural evolution probed by NMR spectroscopy
spellingShingle Aluminum polyphosphate gels structural evolution probed by NMR spectroscopy
Galembeck,André
polyphosphate gels
31P NMR
27Al NMR
aluminum polyphosphate
sol-gel
title_short Aluminum polyphosphate gels structural evolution probed by NMR spectroscopy
title_full Aluminum polyphosphate gels structural evolution probed by NMR spectroscopy
title_fullStr Aluminum polyphosphate gels structural evolution probed by NMR spectroscopy
title_full_unstemmed Aluminum polyphosphate gels structural evolution probed by NMR spectroscopy
title_sort Aluminum polyphosphate gels structural evolution probed by NMR spectroscopy
author Galembeck,André
author_facet Galembeck,André
author_role author
dc.contributor.author.fl_str_mv Galembeck,André
dc.subject.por.fl_str_mv polyphosphate gels
31P NMR
27Al NMR
aluminum polyphosphate
sol-gel
topic polyphosphate gels
31P NMR
27Al NMR
aluminum polyphosphate
sol-gel
description The aim of this work was to investigate how the structure of aluminum polyphosphate gels change upon aging and drying. This is essential if one is interested in using a gel as a matrix to synthesize organic-inorganic hybrid materials. The liquid and solid samples were characterized by 27Al and 31P NMR spectroscopy. Larger polyphosphate chains make the main contribution to gel formation and the smaller units are expelled into the supernatant solution. Polyphosphate chains undergo hydrolysis and chain scission upon gelation. Samples aged in a moisture-rich environment turn into viscous liquids as a consequence of water uptake, followed by extensive hydrolysis. Samples exposed to low relative humidity environments dry yielding brittle samples in which larger chains are stable. Vacuum-dried samples still contain ca. 30%-weight water.
publishDate 2003
dc.date.none.fl_str_mv 2003-12-01
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
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status_str publishedVersion
dc.identifier.uri.fl_str_mv http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532003000600010
url http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532003000600010
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv 10.1590/S0103-50532003000600010
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv text/html
dc.publisher.none.fl_str_mv Sociedade Brasileira de Química
publisher.none.fl_str_mv Sociedade Brasileira de Química
dc.source.none.fl_str_mv Journal of the Brazilian Chemical Society v.14 n.6 2003
reponame:Journal of the Brazilian Chemical Society (Online)
instname:Sociedade Brasileira de Química (SBQ)
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reponame_str Journal of the Brazilian Chemical Society (Online)
collection Journal of the Brazilian Chemical Society (Online)
repository.name.fl_str_mv Journal of the Brazilian Chemical Society (Online) - Sociedade Brasileira de Química (SBQ)
repository.mail.fl_str_mv ||office@jbcs.sbq.org.br
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