Utilize este identificador para referenciar este registo:
https://hdl.handle.net/1822/29652
Título: | Rheological characterization of commercial highly viscous alginate solutions in shear and extensional flows |
Autor(es): | Rodríguez-Rivero, Cristina Hilliou, L. Martin del Valle, Eva M. Galán, Miguel A. |
Palavras-chave: | Rheology Alginate Polyelectrolyte Neutral polymer Strain thinning Chain rigidity |
Data: | 2014 |
Editora: | Springer |
Revista: | Rheologica acta |
Resumo(s): | The rheological properties of sodium alginate in salt-free solutions were studied by steady shear, dynamic oscillatory and extensional measurements. This biopolymer consists of mannuronic and guluronic acid residues that give a polyelectrolyte character. We applied the scaling theories and checked their accordance with polyelectrolyte behaviour for low concentrations with a shift to neutral polymer behaviour at larger concentrations. This nature was supported by the effect of the concentration on the specific viscosity, the relaxation times from steady shear and the longest relaxation times from small amplitude oscillatory shear (SAOS) measurements. To analyze the extensional behaviour of the samples, we conducted a study of dimensionless numbers and time scales where filament thinning driven by viscous, capillary or elastic forces is at play. We conclude that an exponential filament thinning followed by breakup results in the best regimes that describe the experimental data. Besides, the data pointed out that alginate in salt-free concentrated solutions shows strain thinning of the extensional viscosity and chain rigidity, behaviours that cannot be inferred from the shear rheometry. |
Tipo: | Artigo |
URI: | https://hdl.handle.net/1822/29652 |
DOI: | 10.1007/s00397-014-0780-4 |
ISSN: | 0035-4511 1435-1528 |
Versão da editora: | http://link.springer.com/article/10.1007/s00397-014-0780-4 |
Arbitragem científica: | yes |
Acesso: | Acesso restrito UMinho |
Aparece nas coleções: | IPC - Artigos em revistas científicas internacionais com arbitragem |
Ficheiros deste registo:
Ficheiro | Descrição | Tamanho | Formato | |
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rheol acta 2014 alginate.pdf Acesso restrito! | author copy | 1,38 MB | Adobe PDF | Ver/Abrir |