Tuning rheology and aggregation behaviour of TEMPO-oxidised cellulose nanofibrils aqueous suspensions by addition of different acids

Detalhes bibliográficos
Autor(a) principal: Alves, L.
Data de Publicação: 2020
Outros Autores: Ferraz, E., Lourenço, A. F., Ferreira, P. J., Rasteiro, M. G., Gamelas, J. A. F.
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Texto Completo: http://hdl.handle.net/10773/37588
Resumo: The present work intends to study the variations in the rheological properties and aggregation behaviour of TEMPO-oxidised cellulose nanofibrils (CNF) aqueous suspensions, as a function of changes in concentration and systematic changes in the pH, by addition of acids with different anions. It was found that CNF suspensions form strong gels at mass fractions higher than 0.35 % and the gel point is ca. 0.18 %. On the other hand, aggregation is enhanced at acidic pH conditions due to lower charge repulsion among fibrils, leading to an increase of the suspension viscosity. However, distinct rheological behaviours were presented by CNF suspensions as different acids were applied. It was found that phosphate ions resulted in significant aggregation leading to formation of particles of large size and very strong gels, at pH 2.3; distinctly, the presence of acetate ions resulted in lower aggregation, lower particle size and weaker gels, at the same pH value.
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spelling Tuning rheology and aggregation behaviour of TEMPO-oxidised cellulose nanofibrils aqueous suspensions by addition of different acidsCellulose nanofibrilsCharged nanofibrilsRheological propertiesHydrogelsAggregationAcidsProtonationHofmeister seriesThe present work intends to study the variations in the rheological properties and aggregation behaviour of TEMPO-oxidised cellulose nanofibrils (CNF) aqueous suspensions, as a function of changes in concentration and systematic changes in the pH, by addition of acids with different anions. It was found that CNF suspensions form strong gels at mass fractions higher than 0.35 % and the gel point is ca. 0.18 %. On the other hand, aggregation is enhanced at acidic pH conditions due to lower charge repulsion among fibrils, leading to an increase of the suspension viscosity. However, distinct rheological behaviours were presented by CNF suspensions as different acids were applied. It was found that phosphate ions resulted in significant aggregation leading to formation of particles of large size and very strong gels, at pH 2.3; distinctly, the presence of acetate ions resulted in lower aggregation, lower particle size and weaker gels, at the same pH value.Elsevier2023-05-08T12:01:21Z2020-06-01T00:00:00Z2020-06-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10773/37588eng0144-861710.1016/j.carbpol.2020.116109Alves, L.Ferraz, E.Lourenço, A. F.Ferreira, P. J.Rasteiro, M. G.Gamelas, J. A. F.info: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:RCAAP2024-02-22T12:12:44Zoai:ria.ua.pt:10773/37588Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T03:08:12.407178Repositório 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 Tuning rheology and aggregation behaviour of TEMPO-oxidised cellulose nanofibrils aqueous suspensions by addition of different acids
title Tuning rheology and aggregation behaviour of TEMPO-oxidised cellulose nanofibrils aqueous suspensions by addition of different acids
spellingShingle Tuning rheology and aggregation behaviour of TEMPO-oxidised cellulose nanofibrils aqueous suspensions by addition of different acids
Alves, L.
Cellulose nanofibrils
Charged nanofibrils
Rheological properties
Hydrogels
Aggregation
Acids
Protonation
Hofmeister series
title_short Tuning rheology and aggregation behaviour of TEMPO-oxidised cellulose nanofibrils aqueous suspensions by addition of different acids
title_full Tuning rheology and aggregation behaviour of TEMPO-oxidised cellulose nanofibrils aqueous suspensions by addition of different acids
title_fullStr Tuning rheology and aggregation behaviour of TEMPO-oxidised cellulose nanofibrils aqueous suspensions by addition of different acids
title_full_unstemmed Tuning rheology and aggregation behaviour of TEMPO-oxidised cellulose nanofibrils aqueous suspensions by addition of different acids
title_sort Tuning rheology and aggregation behaviour of TEMPO-oxidised cellulose nanofibrils aqueous suspensions by addition of different acids
author Alves, L.
author_facet Alves, L.
Ferraz, E.
Lourenço, A. F.
Ferreira, P. J.
Rasteiro, M. G.
Gamelas, J. A. F.
author_role author
author2 Ferraz, E.
Lourenço, A. F.
Ferreira, P. J.
Rasteiro, M. G.
Gamelas, J. A. F.
author2_role author
author
author
author
author
dc.contributor.author.fl_str_mv Alves, L.
Ferraz, E.
Lourenço, A. F.
Ferreira, P. J.
Rasteiro, M. G.
Gamelas, J. A. F.
dc.subject.por.fl_str_mv Cellulose nanofibrils
Charged nanofibrils
Rheological properties
Hydrogels
Aggregation
Acids
Protonation
Hofmeister series
topic Cellulose nanofibrils
Charged nanofibrils
Rheological properties
Hydrogels
Aggregation
Acids
Protonation
Hofmeister series
description The present work intends to study the variations in the rheological properties and aggregation behaviour of TEMPO-oxidised cellulose nanofibrils (CNF) aqueous suspensions, as a function of changes in concentration and systematic changes in the pH, by addition of acids with different anions. It was found that CNF suspensions form strong gels at mass fractions higher than 0.35 % and the gel point is ca. 0.18 %. On the other hand, aggregation is enhanced at acidic pH conditions due to lower charge repulsion among fibrils, leading to an increase of the suspension viscosity. However, distinct rheological behaviours were presented by CNF suspensions as different acids were applied. It was found that phosphate ions resulted in significant aggregation leading to formation of particles of large size and very strong gels, at pH 2.3; distinctly, the presence of acetate ions resulted in lower aggregation, lower particle size and weaker gels, at the same pH value.
publishDate 2020
dc.date.none.fl_str_mv 2020-06-01T00:00:00Z
2020-06-01
2023-05-08T12:01:21Z
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
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dc.identifier.uri.fl_str_mv http://hdl.handle.net/10773/37588
url http://hdl.handle.net/10773/37588
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv 0144-8617
10.1016/j.carbpol.2020.116109
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dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Elsevier
publisher.none.fl_str_mv Elsevier
dc.source.none.fl_str_mv reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
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