Supercritical Microfluidics: Chemical Reactivity and Nanomaterials Synthesis At High Pressures and Temperatures

The last few years have seen the development of a new field of investigation, so called “Supercritical Microfluidics” with the basic idea to combine the advantages of size reduction provided by microsystems – advanced control of operating parameters, reproducibility, in situ and online characterization, rapid screening, fast mass and heat transfer and low reagent consumption – to the unique properties of supercritical fluids - “hybrids” thermophysical properties, intermediate between liquids and gases, continuously adjustable with small variations of pressure and temperature, gas-like viscosities and diffusivities, liquid-like densities.

The design of microreactors capable of handling working conditions compatible with high pressure fluids opens new ways for characterizing and studying hydrothermal and supercritical fluids processes, generally limited to the use of “blind” stainless steel devices.

This talk will first highlights the main interests of combining supercritical fluids to Microfluidic systems (Supercritical Microfluidics). Some applications of supercritical microreactors will eventually be presented. In particular, we will focus on on-chip supercritical water oxidation of models compounds and on the synthesis of nanomaterials in supercritical media (nanocatalysts with tunable surface funtionalities and ZnO quantum dots).