Titre :
|
The transition zone for gelatin gels as measured by high-frequency rheology
|
Auteurs :
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A. Bot ;
R. Wientjest ;
K. De Haast
|
Type de document :
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article/chapitre/communication
|
Année de publication :
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1997
|
Format :
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p. 191-196
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Langues:
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= Anglais
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Catégories :
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PHYSIQUE ETAT DE LA MATIERE
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Mots-clés:
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RHEOLOGIE
;
APPAREIL DE MESURE
;
MODELE
;
CONCENTRATION
;
DEFORMATION
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Résumé :
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The high-frequency (100 Hz-200 kHz) linear viscoelastic behaviour of gelatin in the transition zone was investigated. During the early stages of ageing, the dynamic shear modulus for a 4 wt% gelatin gel at the gel point at 25 °C was found to vary according to a power law G' proportional to G '' proportional to omega(n), with n approximate to 0.75. Within the framework of a recent model by Groot et al. [J. Chem. Phys., 104, 9202 (1996)], this value is consistent with a result derived earlier from large deformation rheology, suggesting that the network bonds in a gelatin gel are more stretched than an ideally swollen polymer chain. However, ageing effects observed in large deformation experiments are not observed for the small deformation high-frequency data.
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Source :
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Imaging Science Journal, vol.45
|