Aim
Hot-wall reactors are suitable for the specific synthesis of non-oxidic nanoparticles from the gas phase. Nanoparticle properties like size, size distribution and morphology can be controlled and tuned by adjusting flow conditions, pressure and temperature. Especially the scientific investigation of nanoparticle formation and growth requires reactors with good accessibility and multiple measurement and sampling possibilities. Online-techniques such as laser-induced incadescence (LII) and almost undisturbed sampling methods deliver valuable information about particle formation and growth under selected conditions. This information is highly conducive to process optimization as well as to the further development and validation of computational fluid dynamics and modeling of particle formation and growth.

Approach
The HWR50 consists of a vertically mounted fused silica hot wall reactor with a subsequent particle filter for the separation of the synthesized nanoparticles. The reactor enables for a parallel as well as a graded feeding of precursor gases. Therefore, not only pure materials but also core/shell materials such as carbon-coated iron nanoparticles are available. The hot wall reactor can be heated up to 1000°C and can be operated between 10 mbar and atmospheric pressure. The reactor provides a couple of optically and mechanically accessible regions downstream the heating zone. Optical measurements such as LII and laser-induced fluorescence (LIF) and nanoparticle extraction can be realized during operation. Synthesis of up to a few gram per hour is possible for ex-situ characterization and post-processing of as-prepared nanomaterials. Particle sampling and filling is possible under inert gas conditions.

References
Orthner, H.R., Roth, P., Materials Chemistry and Physics 78, 453-458 (2002)

Contact
apl. Prof. Dr. habil. H. Wiggers, Hartmut Wiggers, Tel: +49 (0)203 - 379 8087, IVG