Abstract
The effect of energy density. pH and solid concentration on kinetics of de-agglomeration of hydrophobic silica nano-powder in a high shear mixer and on the rheology of resulting suspensions was investigated and compared with de-agglomeration kinetics and rheology of the suspension of hydrophilic silica nano-powder. In both types of nano-powders large aggregates were broken by fracture and erosion. in hydrophobic nano-powder erosion was more pronounced whilst in hydrophilic nano-powder erosion followed initial fracture of large aggregates. At sufficiently high energy input both hydrophobic and hydrophilic aggregates were broken into nano-aggregates but, even at the highest energy input, those nano-aggregates could not have been broken into single nano-particles. Rheology of the suspensions of hydrophobic nano-aggregates strongly depends on pH and on solid concentration whilst rheology of suspensions of hydrophilic nano-powder is rather weakly dependent on those parameters. (c) 2009 Elsevier B.V. All rights reserved.
| Original language | English |
|---|---|
| Pages (from-to) | 221-226 |
| Number of pages | 6 |
| Journal | Powder Technology |
| Volume | 195 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 1 Nov 2009 |
Keywords
- nano-powders
- De-agglomeration
- Rheology
- Hydrophobic and hydrophilic silica
- pH
- Energy density