Characterization of dextrin hydrogels by FTIR spectroscopy and solid state NMR spectroscopy
Autor(a) principal: | |
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Data de Publicação: | 2008 |
Outros Autores: | , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | https://hdl.handle.net/1822/8161 |
Resumo: | Fourier transform infrared (FTIR) and 13C solid state nuclear magnetic resonance (NMR) spectroscopy were used to study dextrin structural changes occurring upon hydrogel formation by vinyl acrylate (VA) grafting and subsequent free radical polymerization. The degrees of VA substitution (DS) and polymerization (DP) were quantified up to 40%VA by FTIR intensity measurements and partial least squares (PLS)/FTIR, the latter being a faster and less error-prone method. Above 40%VA, both parameters are underestimated by FTIR. A spin counting NMR experiment showed high carbon observabilities for hydrogels and improved PLS/NMR models were achieved for DS and DP determination. Alternative NMR integration methods are hindered by the broad VA peaks and need for area correction, due to their CP dynamics. NMR changes in C1 profile showed that a single helical conformation predominates at lower %VA, being replaced by disordered conformations as %VA increases. Furthermore, a correlation FTIR/NMR study indicated that ring conformations are significantly affected in hydrogels, compared to unpolymerized dextrin. |
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Characterization of dextrin hydrogels by FTIR spectroscopy and solid state NMR spectroscopyDextrinHydrogelFTIRCP/MASPLS2D-COSScience & TechnologyFourier transform infrared (FTIR) and 13C solid state nuclear magnetic resonance (NMR) spectroscopy were used to study dextrin structural changes occurring upon hydrogel formation by vinyl acrylate (VA) grafting and subsequent free radical polymerization. The degrees of VA substitution (DS) and polymerization (DP) were quantified up to 40%VA by FTIR intensity measurements and partial least squares (PLS)/FTIR, the latter being a faster and less error-prone method. Above 40%VA, both parameters are underestimated by FTIR. A spin counting NMR experiment showed high carbon observabilities for hydrogels and improved PLS/NMR models were achieved for DS and DP determination. Alternative NMR integration methods are hindered by the broad VA peaks and need for area correction, due to their CP dynamics. NMR changes in C1 profile showed that a single helical conformation predominates at lower %VA, being replaced by disordered conformations as %VA increases. Furthermore, a correlation FTIR/NMR study indicated that ring conformations are significantly affected in hydrogels, compared to unpolymerized dextrin.Funding is acknowledged from the Foundation for Science and Technology, Portugal, for project POCI/QUI/56229/2004 and grants for H.G. and C.G. (SFRH/22242/2005). The authors also wish to acknowledge CICECO for partial funding of this work.Fundação para a Ciência e a Tecnologia (FCT)Elsevier Ltd.Universidade do MinhoGarcia, HelgaBarros, AntónioGonçalves, CatarinaGama, F. M.Gil, Ana M.2008-072008-07-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttps://hdl.handle.net/1822/8161eng"European Polymer Journal". ISSN 0014-3057. 44:7 (July 2008) 2318-2329.0014-305710.1016/j.eurpolymj.2008.05.013info: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:RCAAP2023-07-21T12:42:56Zoai:repositorium.sdum.uminho.pt:1822/8161Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T19:40:18.147384Repositório 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 |
Characterization of dextrin hydrogels by FTIR spectroscopy and solid state NMR spectroscopy |
title |
Characterization of dextrin hydrogels by FTIR spectroscopy and solid state NMR spectroscopy |
spellingShingle |
Characterization of dextrin hydrogels by FTIR spectroscopy and solid state NMR spectroscopy Garcia, Helga Dextrin Hydrogel FTIR CP/MAS PLS 2D-COS Science & Technology |
title_short |
Characterization of dextrin hydrogels by FTIR spectroscopy and solid state NMR spectroscopy |
title_full |
Characterization of dextrin hydrogels by FTIR spectroscopy and solid state NMR spectroscopy |
title_fullStr |
Characterization of dextrin hydrogels by FTIR spectroscopy and solid state NMR spectroscopy |
title_full_unstemmed |
Characterization of dextrin hydrogels by FTIR spectroscopy and solid state NMR spectroscopy |
title_sort |
Characterization of dextrin hydrogels by FTIR spectroscopy and solid state NMR spectroscopy |
author |
Garcia, Helga |
author_facet |
Garcia, Helga Barros, António Gonçalves, Catarina Gama, F. M. Gil, Ana M. |
author_role |
author |
author2 |
Barros, António Gonçalves, Catarina Gama, F. M. Gil, Ana M. |
author2_role |
author author author author |
dc.contributor.none.fl_str_mv |
Universidade do Minho |
dc.contributor.author.fl_str_mv |
Garcia, Helga Barros, António Gonçalves, Catarina Gama, F. M. Gil, Ana M. |
dc.subject.por.fl_str_mv |
Dextrin Hydrogel FTIR CP/MAS PLS 2D-COS Science & Technology |
topic |
Dextrin Hydrogel FTIR CP/MAS PLS 2D-COS Science & Technology |
description |
Fourier transform infrared (FTIR) and 13C solid state nuclear magnetic resonance (NMR) spectroscopy were used to study dextrin structural changes occurring upon hydrogel formation by vinyl acrylate (VA) grafting and subsequent free radical polymerization. The degrees of VA substitution (DS) and polymerization (DP) were quantified up to 40%VA by FTIR intensity measurements and partial least squares (PLS)/FTIR, the latter being a faster and less error-prone method. Above 40%VA, both parameters are underestimated by FTIR. A spin counting NMR experiment showed high carbon observabilities for hydrogels and improved PLS/NMR models were achieved for DS and DP determination. Alternative NMR integration methods are hindered by the broad VA peaks and need for area correction, due to their CP dynamics. NMR changes in C1 profile showed that a single helical conformation predominates at lower %VA, being replaced by disordered conformations as %VA increases. Furthermore, a correlation FTIR/NMR study indicated that ring conformations are significantly affected in hydrogels, compared to unpolymerized dextrin. |
publishDate |
2008 |
dc.date.none.fl_str_mv |
2008-07 2008-07-01T00:00:00Z |
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 |
https://hdl.handle.net/1822/8161 |
url |
https://hdl.handle.net/1822/8161 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
"European Polymer Journal". ISSN 0014-3057. 44:7 (July 2008) 2318-2329. 0014-3057 10.1016/j.eurpolymj.2008.05.013 |
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 |
Elsevier Ltd. |
publisher.none.fl_str_mv |
Elsevier Ltd. |
dc.source.none.fl_str_mv |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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RCAAP |
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RCAAP |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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1799132947511508992 |