Rheo-NMR study of water-based cellulose liquid crystal system at high shear rates
Autor(a) principal: | |
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Data de Publicação: | 2015 |
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/10400.21/5916 |
Resumo: | Since long ago cellulosic lyotropic liquid crystals were thought as potential materials to produce fibers competitive with spidersilk or Kevlar, yet the processing of high modulus materials from cellulose-based precursors was hampered by their complex rheological behavior. In this work, by using the Rheo-NMR technique, which combines deuterium NMR with rheology, we investigate the high shear rate regimes that may be of interest to the industrial processing of these materials. Whereas the low shear rate regimes were already investigated by this technique in different works [1-4], the high shear rates range is still lacking a detailed study. This work focuses on the orientational order in the system both under shear and subsequent relaxation process arising after shear cessation through the analysis of deuterium spectra from the deuterated solvent water. At the analyzed shear rates the cholesteric order is suppressed and a flow-aligned nematic is observed which for the higher shear rates develops after certain time periodic perturbations that transiently annihilate the order in the system. During relaxation the flow aligned nematic starts losing order due to the onset of the cholesteric helices leading to a period of very low order where cholesteric helices with different orientations are forming from the aligned nematic, followed in the final stage by an increase in order at long relaxation times corresponding to the development of aligned cholesteric domains. This study sheds light on the complex rheological behavior of chiral nematic cellulose-based systems and opens ways to improve its processing. (C) 2015 Elsevier Ltd. All rights reserved. |
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Rheo-NMR study of water-based cellulose liquid crystal system at high shear ratesCelluloseLiquid crystalRheo-NMRSince long ago cellulosic lyotropic liquid crystals were thought as potential materials to produce fibers competitive with spidersilk or Kevlar, yet the processing of high modulus materials from cellulose-based precursors was hampered by their complex rheological behavior. In this work, by using the Rheo-NMR technique, which combines deuterium NMR with rheology, we investigate the high shear rate regimes that may be of interest to the industrial processing of these materials. Whereas the low shear rate regimes were already investigated by this technique in different works [1-4], the high shear rates range is still lacking a detailed study. This work focuses on the orientational order in the system both under shear and subsequent relaxation process arising after shear cessation through the analysis of deuterium spectra from the deuterated solvent water. At the analyzed shear rates the cholesteric order is suppressed and a flow-aligned nematic is observed which for the higher shear rates develops after certain time periodic perturbations that transiently annihilate the order in the system. During relaxation the flow aligned nematic starts losing order due to the onset of the cholesteric helices leading to a period of very low order where cholesteric helices with different orientations are forming from the aligned nematic, followed in the final stage by an increase in order at long relaxation times corresponding to the development of aligned cholesteric domains. This study sheds light on the complex rheological behavior of chiral nematic cellulose-based systems and opens ways to improve its processing. (C) 2015 Elsevier Ltd. All rights reserved.Elsevier SCI LTDRCIPLEcheverria, CoroAlmeida, Pedro L.Feio, GabrielFigueirinhas, JoãoRey, Alejandro D.Godinho, Maria Helena2016-03-18T15:11:56Z2015-05-182015-05-18T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10400.21/5916engECHEVERRIA, Coro; [et al.] - Rheo-NMR study of water-based cellulose liquid crystal system at high shear rates. Polymer. ISSN. 0032-3861. Vol. 65 (2015), pp. 18-250032-386110.1016/j.polymer.2015.03.050metadata only accessinfo: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:RCAAP2023-08-03T09:50:01Zoai:repositorio.ipl.pt:10400.21/5916Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T20:15:07.943459Repositório 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 |
Rheo-NMR study of water-based cellulose liquid crystal system at high shear rates |
title |
Rheo-NMR study of water-based cellulose liquid crystal system at high shear rates |
spellingShingle |
Rheo-NMR study of water-based cellulose liquid crystal system at high shear rates Echeverria, Coro Cellulose Liquid crystal Rheo-NMR |
title_short |
Rheo-NMR study of water-based cellulose liquid crystal system at high shear rates |
title_full |
Rheo-NMR study of water-based cellulose liquid crystal system at high shear rates |
title_fullStr |
Rheo-NMR study of water-based cellulose liquid crystal system at high shear rates |
title_full_unstemmed |
Rheo-NMR study of water-based cellulose liquid crystal system at high shear rates |
title_sort |
Rheo-NMR study of water-based cellulose liquid crystal system at high shear rates |
author |
Echeverria, Coro |
author_facet |
Echeverria, Coro Almeida, Pedro L. Feio, Gabriel Figueirinhas, João Rey, Alejandro D. Godinho, Maria Helena |
author_role |
author |
author2 |
Almeida, Pedro L. Feio, Gabriel Figueirinhas, João Rey, Alejandro D. Godinho, Maria Helena |
author2_role |
author author author author author |
dc.contributor.none.fl_str_mv |
RCIPL |
dc.contributor.author.fl_str_mv |
Echeverria, Coro Almeida, Pedro L. Feio, Gabriel Figueirinhas, João Rey, Alejandro D. Godinho, Maria Helena |
dc.subject.por.fl_str_mv |
Cellulose Liquid crystal Rheo-NMR |
topic |
Cellulose Liquid crystal Rheo-NMR |
description |
Since long ago cellulosic lyotropic liquid crystals were thought as potential materials to produce fibers competitive with spidersilk or Kevlar, yet the processing of high modulus materials from cellulose-based precursors was hampered by their complex rheological behavior. In this work, by using the Rheo-NMR technique, which combines deuterium NMR with rheology, we investigate the high shear rate regimes that may be of interest to the industrial processing of these materials. Whereas the low shear rate regimes were already investigated by this technique in different works [1-4], the high shear rates range is still lacking a detailed study. This work focuses on the orientational order in the system both under shear and subsequent relaxation process arising after shear cessation through the analysis of deuterium spectra from the deuterated solvent water. At the analyzed shear rates the cholesteric order is suppressed and a flow-aligned nematic is observed which for the higher shear rates develops after certain time periodic perturbations that transiently annihilate the order in the system. During relaxation the flow aligned nematic starts losing order due to the onset of the cholesteric helices leading to a period of very low order where cholesteric helices with different orientations are forming from the aligned nematic, followed in the final stage by an increase in order at long relaxation times corresponding to the development of aligned cholesteric domains. This study sheds light on the complex rheological behavior of chiral nematic cellulose-based systems and opens ways to improve its processing. (C) 2015 Elsevier Ltd. All rights reserved. |
publishDate |
2015 |
dc.date.none.fl_str_mv |
2015-05-18 2015-05-18T00:00:00Z 2016-03-18T15:11:56Z |
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/10400.21/5916 |
url |
http://hdl.handle.net/10400.21/5916 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
ECHEVERRIA, Coro; [et al.] - Rheo-NMR study of water-based cellulose liquid crystal system at high shear rates. Polymer. ISSN. 0032-3861. Vol. 65 (2015), pp. 18-25 0032-3861 10.1016/j.polymer.2015.03.050 |
dc.rights.driver.fl_str_mv |
metadata only access info:eu-repo/semantics/openAccess |
rights_invalid_str_mv |
metadata only access |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Elsevier SCI LTD |
publisher.none.fl_str_mv |
Elsevier SCI LTD |
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 |
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RCAAP |
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RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
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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1817551502327152640 |