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

Acids Aggregation Cellulose nanofibrils Charged nanofibrils Hofmeister series Hydrogels Protonation Rheological properties

Journal

Carbohydrate polymers
ISSN: 1879-1344
Titre abrégé: Carbohydr Polym
Pays: England
ID NLM: 8307156

Informations de publication

Date de publication:
01 Jun 2020
Historique:
received: 14 11 2019
revised: 27 02 2020
accepted: 02 03 2020
entrez: 4 4 2020
pubmed: 4 4 2020
medline: 4 4 2020
Statut: ppublish

Résumé

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.

Identifiants

pubmed: 32241451
pii: S0144-8617(20)30283-6
doi: 10.1016/j.carbpol.2020.116109
pii:
doi:

Types de publication

Journal Article

Langues

eng

Sous-ensembles de citation

IM

Pagination

116109

Informations de copyright

Copyright © 2020 Elsevier Ltd. All rights reserved.

Auteurs

L Alves (L)

CIEPQPF, Department of Chemical Engineering, University of Coimbra, Pólo II - R. Silvio Lima, 3030-790 Coimbra, Portugal. Electronic address: luisalves@ci.uc.pt.

E Ferraz (E)

Techn&Art, Polytechnic Institute of Tomar, Quinta do Contador, Estrada da Serra, PT - 2300-313 Tomar, Portugal; Geobiotec, Geosciences Department, University of Aveiro, Campus Universitário de Santiago, PT - 3810-193 Aveiro, Portugal.

A F Lourenço (AF)

CIEPQPF, Department of Chemical Engineering, University of Coimbra, Pólo II - R. Silvio Lima, 3030-790 Coimbra, Portugal.

P J Ferreira (PJ)

CIEPQPF, Department of Chemical Engineering, University of Coimbra, Pólo II - R. Silvio Lima, 3030-790 Coimbra, Portugal.

M G Rasteiro (MG)

CIEPQPF, Department of Chemical Engineering, University of Coimbra, Pólo II - R. Silvio Lima, 3030-790 Coimbra, Portugal.

J A F Gamelas (JAF)

CIEPQPF, Department of Chemical Engineering, University of Coimbra, Pólo II - R. Silvio Lima, 3030-790 Coimbra, Portugal. Electronic address: jafgas@eq.uc.pt.

Classifications MeSH