Abstract
Grinding behavior of nanoparticles in an attritor mill and the minimum achievable particle size are strongly influenced by the suspension
stability. In the present work, suspension stability (i.e. ζ-potential) of nanoparticles was studied by measuring pH as a function of grinding time
in the wet milling process. It was found that after a certain time in an attritor mill, there is no further size reduction and the average product
particle size increases monotonically. One of the reasons is that the production of submicron particles leads to more particle–particle interactions
and consequently pH of the suspension decreases with grinding time. Usually pH value is related to suspension stability and it can be enhanced by
addition of NaOH solution. The maximum negative ζ-potential of −51.2mV was obtained at pH of 12 for silica. The higher the ζ-potential with the
same polarity, higher will be the electrostatic repulsion between the particles. Hence, the maximum electrostatic repulsion force was maintained by
the adjustment of pH value in wet milling. The experiments were conducted at different pH conditions which were maintained constant throughout
the experiments and nanosized particles were obtained consequently.
stability. In the present work, suspension stability (i.e. ζ-potential) of nanoparticles was studied by measuring pH as a function of grinding time
in the wet milling process. It was found that after a certain time in an attritor mill, there is no further size reduction and the average product
particle size increases monotonically. One of the reasons is that the production of submicron particles leads to more particle–particle interactions
and consequently pH of the suspension decreases with grinding time. Usually pH value is related to suspension stability and it can be enhanced by
addition of NaOH solution. The maximum negative ζ-potential of −51.2mV was obtained at pH of 12 for silica. The higher the ζ-potential with the
same polarity, higher will be the electrostatic repulsion between the particles. Hence, the maximum electrostatic repulsion force was maintained by
the adjustment of pH value in wet milling. The experiments were conducted at different pH conditions which were maintained constant throughout
the experiments and nanosized particles were obtained consequently.
| Original language | English |
|---|---|
| Pages (from-to) | 120-124 |
| Number of pages | 4 |
| Journal | Particuology |
| Volume | 6 |
| Issue number | 2 |
| Publication status | Published - 20 Mar 2008 |