Supercritical fluids: Nanotechnology and select emerging applications

In this paper, a selected list of emerging applications of supercritical fluids (SCFs) are presented. In particular, demonstrated facts for the promise of the nanoscale science and technology and its overlap or interface with the SCFs technology are presented. It is argued that nanoengineered materials at the nanoscale have mechanical, optical, chemical, and electrical properties quite different from the bulk material. Examples of enhanced performance of many such materials when they are used in practical applications are given. SCFs, in particular carbon dioxide, on account of their special properties such as zero surface tension, low viscosity, and high solubility, enable them to play a critical role in many advanced technology applications. For example, as miniaturization efforts approach the nanoscale, surface tension forces become an important factor in many nanotechnology processes such as lithography in the electronic industry. In particular, the zero-surface-tension property of the SCFs presents them as a natural choice for nanotechnology processes. Cases are presented where SCF technology could enhance the advancement of nanotechnology or when the two technologies could have synergistic contributions to the synthesis and design of new materials and possibilities are presented. For example, advances in nanoscience and supercritical fluids have contributed to a better design and understanding of the composition, size, and structure of catalysts, crystals, sol - gels, and composite material performance.