Impact of formulation and operating parameters on particle size and grinding media wear in wet media milling of organic compounds - A case study for pyrene

- Electrosteric particle stabilization by polymer-surfactant complex.
- Grinding media wear is reduced by employing a polymeric additive.
- Sub 100 nm particles are produced at low stress energies and high stress numbers.
- Product contamination can be minimized by optimizing the stress energy.
- Grinding media material has a significant influence on the generation of wear.

This study presents the influence of process and formulation parameters on fine grinding of the crystalline organic model compound pyrene. Submicron particles were produced by wet media milling in water. By applying an electrosteric stabilization and optimized process parameters, particle sizes below 100 nm were obtained. Additionally, the influence of formulation and process parameters on grinding media wear were investigated. The product formulation with an ionic surfactant and a nonionic polymer was identified as a significant parameter to reduce the grinding wear. Furthermore, the set of operating parameters as well as the choice of grinding media material were found as key parameters to reduce product contamination. Grinding media wear is proportional to the specific energy input and can be minimized by optimizing the stress energy of grinding media.

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