Project Details
Projekt
Modeling of the precursor chemistry - development, reduction and optimization of reaction mechanisms for decomposition and combustion of organometallic compounds
Applicant
Dr.-Ing. Irenäus Wlokas
Subject Area
Technical Chemistry
Term
from 2015 to 2024
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 262219004
The targeted development of scalable processes for the gas-phase synthesis of tailored nanoparticles requires detailed knowledge of reaction kinetics and particle dynamics. For the Si-C-O-H and Fe-O-H material systems, the database has reached the critical size on the basis of which the reaction mechanisms already developed can be improved. For this purpose, the intermediates important for particle formation are identified and their kinetic and thermodynamic properties are approximated using modern machine learning methods. Past work on the iron system has shown that the chemical kinetics of surface reactions cannot be neglected and that particle formation can play a role at virtually any point in the flame structure. Particles form as soon as the saturation vapor pressure is exceeded. However, they also disappear without a condition prevailing that would lead one to expect complete evaporation, to reappear as soon as the particle growth species exist and thermodynamics permit it. The intervening disappearance of the particles can be plausibly explained chemically if reactions at the surface are considered, similar to the oxidation of soot. In the case of metals, these oxidation products have a very small vapor pressure or even have no solid equivalent. Therefore, the project has two main objectives: (1) A consistent extension of the kinetic and thermodynamic database for already investigated material systems using modern machine learning methods, and (2) development of a consistent and robust concept for describing the surface reactions that change the particle composition and build up or break down the particles. The reaction mechanisms will be developed in close cooperation with TP1 (Schulz | Fikri | Somnitz), TP2 (Kasper), TP3 (Wiggers), TP4 (Winterer) and TP7 (Endres | Schulz), as well as with the group Rahinov (Mercator Fellow of FOR 2284, Tel Aviv) providing data and validation targets. The validated and, if necessary, reduced reaction mechanisms will be used mainly by TP5 (Kruis) and TP9 (Kempf | Wlokas) in flow simulations coupled with the particle formation.
DFG Programme
Research Units
Co-Investigator
Professor Dr.-Ing. Andreas Kempf
