“Creation of Synergies in Tailor-made Mixtures of Heterogeneous Powders: Hetero Aggregations of Particulate Systems and their Properties” (SPP 2289)
Deadline: 14. November 2023
In May 2020, the Senate of the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) established the Priority Programme “Creation of synergies in tailor-made mixtures of heterogeneous powders: Hetero aggregations of particulate systems and their properties” (SPP 2289). The programme is designed to run for six years. The present call invites proposals for the second three-year funding period (starting app. in mid-2024).
Mixing of disperse systems (particles and powders) is a traditional unit operation of process engineering which is of central importance in various technological areas. Applications of mixed particulate systems range from processing of food, pharmaceutical and chemical substances to material processing and materials engineering. Functional mixing of different particle types (hetero-aggregation) has the potential to create outstanding new properties of dispersed products, which depend on the mixture composition (e.g. number of components, concentration, total quantity) and on various secondary process conditions (e.g. agglomeration, coating). In this context, a new product property can emerge from the direct contact of different particles (hetero-contact) and thus from the resulting interface between the respective particular components. Many applications have shown that these hetero-contacts are of fundamental importance for specific functional properties. In most cases, the new properties result from the transfer of charges, mass, heat, forces or moments without the need of a chemical reaction of its components. The quality of such a particulate mixture is thus directly linked to the contact points and interfaces of different particles and the details of the interaction between its species in contact. The new property from the contact zone controls the material and product properties of the entire system that is referred to as hetero-contact in the context of SPP 2289. Direct information about hetero-contact quality (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 (quality of the mixture and material function). At the same time, the hetero-aggregation process for creating such hetero-contacts needs to be investigated and controlled.
The main technical goals and development areas of the Priority Programme SPP 2289 therefore are
- the development of sophisticated methods for the characterisation of hetero-aggregates in disperse systems;
- the development of suitable process diagnostics that feature component-specific detection;
- the derivation of proper process descriptions and simulations with validated models (based on particle, continuum and/or population) for mixtures of particle systems with sizes < 1 µm and
- the establishment of efficient model couplings (e.g. DEM-CFD) for the ab-initio gas phase process design.
These goals aim to create a fundamental understanding of the relevant mixing phenomena on length scales in the sub-micrometer range as well as their modelling and transfer into applications of tailored hetero-aggregated particulate systems and aggregation processes.