Project Details
Projekt
Agglomeration applying high intensity mixing (mechano-fusion) – An integrated approach towards the synthesis of tailored hetero-aggregates combining experiments with 2D and 3D structural characterization via image analysis and stochastic modeling
Subject Area
Mechanical Process Engineering
Term
since 2021
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 462365306
The special properties of hetero-aggregates derive from the mixing state and the particle-particle contacts within the aggregate. The number of contacts as well as microscopic material interaction at the contact play a decisive role regarding macroscopic application properties. Examples to be named are transport properties like electric, ionic or thermal conductivity. In the first funding period (FP) we investigated the mixing and, therefore, the geometric structure of the aggregates, where the project applies the mechano-fusion process, which is situated between grinding and high-intensity mixing processes, to generate hetero-aggregates from primary nano-, submicron- and microsized particle systems. The process is used to generate predominantly core particles with a hetero-aggregate coating. The hetero-aggregates are then submitted to 2D- and 3D-characterization methods to quantify the state of mixing of the primary particles within the individual aggregate structures. The analysis uses methods of spatial stochastic modeling in order to create virtual aggregates, i.e., simulated aggregates, and, in this way, to generate a large database which is necessary for the application of machine learning algorithms. The scientific work in the second FP focuses on the hetero-contacts themselves, which are generated by the high-intensity mixing process. The hypothesis is that these processes provide a high degree of freedom in the design of hetero-aggregates, since not only the geometric orientation and positioning of the different contributing particles is addressed, but also the intensity of the contact. With the high specific mixing power applied, the contact area can be geometrically modified, e.g., plastically deformed, to enlarge and intensify the contact between the two materials. At the contact, further interactions of the materials can be introduced, such as cold welding and interdiffusion of the two materials. The quantification uses different methods of atomic force microscopy, which provide insight into the local geometry, composition and electrical properties. The effects at the particle-particle-interfaces of the contacts within the hetero-aggregate define new and additional functionalities and contribute to the final property function of the hetero-aggregate system at least to the same extent as the geometric mixing state of the primary particles. In this way quantitative structure-property relationships will be derived for 3D hetero-aggregates. To achieve this goal, super-resolution of image data will be performed and synthetic hetero-aggregates, so-called digital twins, will be generated by drawing realizations from the spatial stochastic models developed in the first FP. The structure-property relationships will be used for tailoring hetero-aggregate particle systems with optimized geometric structure and pre-set functional properties.
DFG Programme
Priority Programmes
