| Titre : |
Rheological and texture analysis methods for quantifying yield value and level of thixotropy |
| Type de document : |
texte imprimé |
| Auteurs : |
Slobodanka Tamburic, Auteur ; Helen Sisson, Auteur ; Milica C. Stevic, Auteur ; Neil Cunningham, Auteur |
| Année de publication : |
2017 |
| Article en page(s) : |
p. 24-30 |
| Note générale : |
Bibliogr. |
| Langues : |
Anglais (eng) |
| Catégories : |
Cosmétiques -- Texture
Emulsions -- Emploi en cosmétologie
Formulation (Génie chimique)
Rhéologie
Thixotropie
|
| Index. décimale : |
668.5 Parfums et cosmétiques |
| Résumé : |
The objective of this study was to compare different methods for the assessment of yield stress and level of thixotropy in semisolid emulsions, using three instruments ; an air-bearing controlled-stress rheometer, a T-bar viscometer and a texture analyser. The following methods were used to assess the yield stress : a low-rotation T-bar test, a shear stress sweep, a shear rate sweep, an oscillatory stress sweep and an immersion/de-immersion test on the texture analyser. The level of thixotropy was assessed by : a hysteresis loop test, a three-step thixotropy test and a repeated immersion/de-immersion test.
A good linear régression fit was found between increasing polymer concentration and yield stress measured by the T bar test, oscillatory stress sweep and immersion/de-immersion test, while no such fit existed in the cases of the shear rate sweep and shear stress sweep. There was good correlation between the two rheological methods for detecting the level of thixotropy, the hysteresis loop and the three-step thixotropy test.
The most consistent yield value results were obtained using the low-rotation T-bar test and the oscillatory stress sweep test. Under the experimental conditions of this study, bath three-step thixotropy and hysteresis loop test have proven reliable in assessing the level of thixotropy. The repeated immersion/de-immersion test could also be employed to provide information on irnmediate structural recovery. |
| Note de contenu : |
- Quantifying the yield stress
- Quantifying the level of thixotropy
- Table 1. The formulation of the semisolid w/o emulsion used in the study
- Table 2. Yield stress values obtained using six different methods, five experimental and one based on mathematical model (Hershel-Buckley equation)
|
| En ligne : |
https://drive.google.com/file/d/1G-wIwT08zGStmeFJJEai0BlJEEbEb8aD/view?usp=drive [...] |
| Format de la ressource électronique : |
Pdf |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=28730 |
in SOFW JOURNAL > Vol. 143, N° 6 (06/2017) . - p. 24-30
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Rheological and texture analysis methods for quantifying yield value and level of thixotropy in SOFW JOURNAL, Vol. 143, N° 6 (06/2017)
