| Autor: |
Olga Chernoburova, Mathieu Jenny, Sébastien Kiesgen De Richter, Maude Ferrari, Akira Otsuki |
| Jazyk: |
angličtina |
| Rok vydání: |
2018 |
| Předmět: |
|
| Zdroj: |
Colloids and Interfaces, Vol 2, Iss 4, p 41 (2018) |
| Druh dokumentu: |
article |
| ISSN: |
2504-5377 |
| DOI: |
10.3390/colloids2040041 |
| Popis: |
This study investigates dilute aqueous suspensions of bentonite particles using magnetic resonance imaging (MRI) velocimetry. Four different chemical conditions are tested to investigate the influence of pH and type of monovalent electrolyte on the local rheological behavior of bentonite suspensions. The results indicate the shear banding in a dilute suspension of 0.1 vol.% solid due to the formation of a continuous three-dimensional particle network under a certain chemical environment (i.e., pH 4 in 1 × 10−2 M KNO3). This network is responsible for the existence of the yield stress in that dilute suspension. Structural changes induced by modification of suspensions’ chemistry are examined via scanning electron microscopy. A previously established method based on processing the torques acquired via conventional rheometric measurement is also applied as an alternative way to recover local flow information. Within the shear rate range covered by our MRI velocimetry, the results of both methods show good agreement. This study suggests that the existence of a master curve (or global flow curve) for dilute suspensions is dependent on the bentonite particle organization, which is influenced by the suspension chemistry and the previous flow history. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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