Mathematical modelling of the nanopowders production in Inductively Coupled Plasma reactors

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The production of nanopowders, whose properties differ from the bulk material due to their size close to molecular dimensions, is a nanotechnology that has already had an important industrial impact. Often these materials have completely new properties. Nanometallic powders, nanoceramics or nanocomposites have mechanical, chemical, optical, magnetic and electronic properties that are enhanced compared to micrometric powders with the same chemical composition. For example, micron- sized iron oxide which is has been used as a ferromagnetic recording material for decades acquires at nanometric sizes super-paramagnetic capabilities at room temperature. Energetic materials are examples of nanopowders properties change compared to the micrometric equivalent, nano-aluminum powders have a spontaneous ignition strongly size-dependent. Among the technologies available to produce nanopowders at industrial scale, the Inductively Coupled Plasma (ICP) presents numerous advantages: high temperatures to vaporize precursors of any type, relatively large size and low velocities with a controlled chemical environment. As the flow, temperature and concentration fields in such reactors can be very complex, and since the nanopowders produced in such reactors depend heavily on these fields, a complete characterization is of outmost importance in the design of ICP nanopowders production reactors. It is the objective of this program to develop a mathematical model of the nanopowders production in an ICP reactor that will enable scientists and engineers to design and optimize the reactors. The project will involve first a fundamental mathematical modelling study of the physico-chemical phenomena dealing with: 1) homogeneous nucleation theory 2) nanoparticle surface reaction rates 3) nanoparticle aggregation. It will further involve an applied mathematical, numerical and engineering study that will deal with: 1) the state of the art of the mathematical modelling of nanoparticle production in thermal plasmas 2) the implementation and validation of the Population Balance Equations solution methods (Method Of Moments and Nodal methods) 3) a comprehensive 3-D modelling study of the quenching methods used in industrial thermal plasma reactors 4) the optimization of the numerical model in the open-source platform OpenFOAM.