Mechanische Erzeugung von Nanopartikeln in Rührwerkskugelmühlen (English shop)

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Stefan Mende’s dissertation investigates the mechanical production of nanoparticles in stirred media mills, focusing on wet grinding processes and the parameters influencing particle size reduction. The research examines the comminution behavior of aluminum oxide (Al₂O₃), suspension stability, and grinding media wear. Experimental investigations analyze the effects of grinding media size, stirrer tip speed, solids concentration, and specific energy input on grinding performance. Particular attention is given to electrostatic suspension stabilization through controlled pH adjustment to prevent particle reagglomeration. The results demonstrate that mechanical grinding can produce particles smaller than 10 nm. The study also investigates mechanochemical surface transformations and the formation of aluminum hydroxide phases, including bayerite and gibbsite. Furthermore, the findings confirm the existence of optimal stress energies that provide maximum particle fineness at different specific energy inputs. Suspension rheology is shown to influence grinding media wear and resulting product contamination. The dissertation contributes to understanding nanoscale comminution mechanisms and provides a scientific basis for optimizing wet grinding processes in stirred media mills.