Métrologie des nanoparticules dans un plasma froid capacitif basse pression : développement de diagnostics de métrologie des nanoparticules

摘要

Dust nanoparticles metrology has become a major scientific and industrial issue in order to control the characteristics of nano-objects (size, density, etc.). For industrial interests it concerns processes control and monitoring, manufactured products quality, human being and environment protection. It is therefore, crucial to find innovative methods of characterization and easy to implement and to handle. The objective of this research program was to develop and optimize solutions for characterizing nanoparticles in dry process and environment using a plasma (promoting disagglomeration of the studied powders). The presence of nanoparticles substantially altering the electrical characteristics of the plasma, we have, at first, developed a diagnostic based on the electrical characteristics of the discharge and the plasma. This method allows the determination the average nanoparticles size and concentration trapped in the plasma gas phase. Then, in a second step, we developed a diagnostic based on multi-angle laser light scattering, allowing us to get the size and the average density of the nanoparticles in the plasma, but also their refractive index. We finally focused our interest on the optimization of the plasma-assisted sedimentation of nanoparticles to obtain their size distribution especially for particles having sizes below 10 nm. The correlation of these three diagnostics gives us, so an efficient and reliable diagnostic for the global characterization in terms of size, density and optical properties of nanoparticles trapped in the plasma.