Supercritical microfluidics: Opportunities in flow-through chemistry and materials science

Working under supercritical conditions at microscale combines the advantages of size reduction provided by microsystems to the unique properties of supercritical fluids (SCFs). The so-called “supercritical microfluidics” therefore addresses the limitations of both macroscale SCFs reactors and conventional liquid microfluidic reactors. In this review, we present recent developments in supercritical microfluidics processes with the design of microreactors capable of working under pressure and temperature, some general characteristics of supercritical microflows and, through selected examples, flow-through chemistry and nanocrystals synthesis in supercritical microreactors.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The “supercritical microfluidics” addresses the limitations of both macroscale SCFs reactors and conventional liquid microfluidic reactors. ► The development of SCFs-compatible microsystems has evolved from simple tubings to “on chip” supercritical microreactors, systems integrating control of operating parameters with in situ and online characterization techniques. ► The supercritical microflows combine the advantages of SCFs (low viscosities, high diffusivities) with these of liquid microflows (large surface to volume ratios). ► The continuous supercritical microfluidics has opened new potentialities for chemistry supercritical water and carbon dioxide. ► In the field of nanocrystals synthesis, supercritical microfluidics offers the opportunity to synthesize high quality nanocrystals.