(202e) Gas-Phase Nanoparticle Production, Handling and Separation by Aerodynamic Effects in Supersonic Expansion

Nanoparticle-assembled materials are of great commercial interest for applications in electrochemistry, catalysis or gas sensing due to their high porosity and high specific surface area. Here, a gas-phase process for controlled production of such nanostructured particulate thin films based on high-temperature aerosol synthesis is presented. Nanoparticles are synthesized in a Pulsed Microplasma Cluster Source (PMCS), which is able to deliver highly collimated and intense pulsed nanoparticle beams. Before deposition, the beams are focussed using nozzle systems while particles are manipulated and aerodynamically size-selected as the physical and chemical properties of cluster assembled materials are strictly related to the properties of the nanoparticles free in the beam. Furthermore, the process allows analysis of nanoparticles prior to deposition, not only in terms of mass distribution, but also from the point of view of particle structure, electronic properties, and thermodynamic state. Nanostructured thin films prepared with this approach have been used as active components in gas and humidity sensors and fuel cells. The high particle beam intensity allows deposition rates of about 100 µm/h on 1cm2 of covered area (in the example of carbon nanoparticles), sufficient to develop routes toward industrial production of nanostructured thin films.