Supplementary Material for the Dissertation "Characterization of Coated Particles from Mechano-Fusion"

The dry particle coating process of mechano-fusion (MF) is of interest for a variety of applications, ranging from pharmaceuticals to battery materials. In this work, MF was used to produce hetero-aggregate type coated particles. Dense, discrete and homogeneous monolayer coatings were formed for the particle system consisting of spherical alumina host particles and spherical polystyrene guest particles over a wide parameter space of the available MF device. Increasing the processing intensity, mainly by increasing the rotational speed, led to guest particle deformation and even comminution. The hetero-aggregate microstructure was investigated from different perspectives. Correlating a hetero-aggregate microstructural property (specific surface area) with the macroscopic property of flowability revealed distinct structure–property groups, detailing the influence of MF process parameters. Dry laser diffraction provided information beyond the apparent hetero-aggregate particle size, e.g., on the guest particle aggregation and deformation state. Insight into the 3D structure and morphology of the coating, as well as the guest particle connectivity, was gained through micro-computed tomography (micro-CT), by computing, e.g., coating thickness and guest particle distances. Atomic force microscopy allowed for the guest particle-discrete quantification of deformation. The analyses via micro-CT were extended to a model battery particle system, which exhibited continuous coatings. Since the observed hetero-aggregate structures are not specific to MF, the characterization workflows are transferable to other particle systems and dry coating processes.