Abstract
Rheological studies of boehmite sols based on pH was (1) to study the nature of flow properties of the boehmite sols and (2) to identify the sol-gel transition of boehmite sols with the change of pH of the liquid. It is evident that the shear rate and viscosity of the liquid exhibit a pseudoplastic (shear thinning) flow behavior for all pH level. The transformation of sol-gel at low pH probably due to the hydrogen bond between the layers of the boehmite structure. The temperature has an appreciable effect on the activation energy during the sol-gel transition. The flow activation energies δEn are in the range of 1.75 to 6.25 J mol-1 at temperature 298-384 K. Based on these results, the flow activation energy of boehmite sols sharply decreases with decreasing the pH. The flocculation of the suspension at pH 4 to 1 showed to be favorable in term of enhanced density of boehmite.
Original language | English |
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Pages (from-to) | 2327-2333 |
Number of pages | 7 |
Journal | Journal of Applied Sciences |
Volume | 11 |
Issue number | 13 |
DOIs | |
Publication status | Published - 2011 |
Externally published | Yes |
Keywords
- Activation energy
- Flow behavior index
- Pseudoplastic behavior
- Rheology
- Sol-gel