SPP 2289:  Creation of synergies in tailor-made mixtures of heterogeneous powders: Hetero aggregations of particulate systems and their properties

• Subject Area: Thermal Engineering/Process Engineering
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 441399220

The mixing of disperse systems (particles and powders) is a traditional unit operation in process engineering. The applications of mixed particulate systems range from the processing of food, pharmaceutical and chemical substances to materials processing and materials engineering. Functional mixing of different particle types (hetero-aggregation) has the potential to create outstanding new properties of disperse products that depend on the mixture composition and various secondary process conditions. A new product property can be created by the direct contact of different particles (heterocontact) and thus by the resulting interface between the respective subcomponents. Many applications have shown that these hetero-contacts are of fundamental importance for certain functional properties. In most cases, the new properties result from the transfer of charges, mass, heat, forces or moments without the need for a chemical reaction between the components. The quality of such a particle mixture is therefore directly related to the contact points and interfaces of the different particles and the details of the interaction between their species in contact. The new property from the contact zone controls the material and product properties of the entire system, which is referred to as hetero-contact in the context of SPP. Direct information on the quality of the hetero-contact (e.g. number of contacts, transport properties between different particle types) could therefore form the basis for a fundamental description of the new properties of the particle mixture. At the same time, the hetero-aggregation process for generating such hetero-contacts must be investigated and controlled. In the remaining three years of the SPP, research will increasingly focus on specific material functions of the hetero-aggregated particulate systems, which will be verified and linked to the process parameters. This focus in turn places special demands on adapted process measurement and control techniques as well as on material and particle characterization. In detail, the SPP has the following objectives: - Utilization of previous findings for multi-stage processes for the production of hetero-aggregates with integrated process control. This includes aerosol processes for the defined generation of hetero-aggregates, with adequate process diagnostics for the detection of mixing processes. - Utilization and coupling of various CFD, particle and reaction models and development of a holistic simulation environment for the design of material functions. - Establishment of standard procedures for the characterization of hetero-aggregates in the sub-micrometer range using sample trains from rapid aggregation processes and tomographic methods for the characterization of hetero-aggregates.

• DFG Programme: Priority Programmes
• International Connection: USA

Projects

• 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 (Applicants Peuker, Urs ;  Schmidt, Volker )
• Bipolar electrospray for the synthesis of defined hetero-aggregates: Process design and in situ diagnostics (Applicants Weber, Alfred ;  Will, Stefan )
• Charge-induced mixing of particles for the formation of structured materials and their comprehensive characterization (Applicant Lübbert, Christian )
• Coordination Funds (Applicant Mädler, Lutz )
• DeepMixing II – Tailoring sensor properties of semiconducting metal oxide nanoparticle hetero-aggregates formed in an aerosol mixing zone (Applicants Barsan, Nicolae ;  Mädler, Lutz ;  Rosenauer, Andreas )
• Enhancing Gas-Phase Generation of Electrocatalytic Hetero-Aggregates via Advanced Diagnostics and Performance Evaluation (Applicants Endres, Torsten ;  Wiggers, Hartmut )
• Formulation of hetero-aggregates in continuously-operated opposed jet fluidized beds (Applicants Bück, Andreas ;  Schmidt, Jochen )
• Hetero-aggregation of colloidal silica and carbon black in flames (Applicant Rhein, Frank )
• Hetero-aggregation of fine particles in supersonic flow for the tailor-made surface coating (Applicant Antonyuk, Sergiy )
• Hetero-aggregation of fluidized nanoparticles and solid-containing aerosol droplets (Applicant Tsotsas, Evangelos )
• Hetero-aggregation of nanoparticles in advective environments (Applicant Kronenburg, Andreas )
• Hetero-contacts in functional oxide aggregates: Descriptors of heterogeneity, aggregate design and process simulation towards nanostructured optical precursor materials (Applicants Wondraczek, Lothar ;  Wondraczek, Katrin )
• Heteroaggregate Formation Dynamics in the Dispersed Phase – Modeling, Simulation, and Experiments (Applicants Kaiser, Sebastian ;  Wlokas, Irenäus )
• Hybrid modelling of heteroagglomeration in gas-borne flows using CFD-DEM simulation and machine learning methods (Applicant Schilde, Carsten )
• Ion and electron conducting hetero-aggregates for electrochemical applications (Applicants Janek, Jürgen ;  Kwade, Arno )
• Laser-optical in situ detection and imaging of gas-borne heteroaggregate formation (Applicant Endres, Torsten )
• Numerical prediction of hetero-aggregate composition from electrospray processes and their product-oriented optimisation (Applicant Sommerfeld, Martin )
• Quantification of the mixing zone and intensification of the mixing process of two nanoparticle producing flames for the design of hetero-contacts (Applicants Fritsching, Udo ;  Mädler, Lutz )
• Realization and analysis of jet-based direct mixing gas phase agglomeration for the formation of hetero-agglomerates with new properties (Applicants Kruggel-Emden, Harald ;  Schmidt, Eberhard )
• Spouted bed processing for structuring of conductive battery hetero-aggregates (Applicant Heinrich, Stefan )
• Tailored hetero-aggregates from gas phase synthesis for heterogeneously catalyzed transient reactions (Applicants Güttel, Robert ;  Mädler, Lutz )

• Spokesperson: Professor Dr.-Ing. Lutz Mädler