Copper Nanoparticle Synthesis in Compressed Liquid and Supercritical Fluid Reverse Micelle Systems

Abstract

Synthesis of copper nanoparticles within sodium bis(2-ethylhexyl)sulfosuccinate (AOT) reverse micelles was performed by implementing compressed liquid and supercritical fluid (SCF) alkanes as the bulk solvent of the microemulsion system. In this reverse micelle reaction media, the role of the anionic surfactant AOT is twofold. Initially, the AOT creates a thermodynamically stable microemulsion system consisting of water and metal ions encased within an AOT surfactant reverse micelle and dispersed within a bulk oil phase. The AOT surfactant also acts as a stabilizing ligand where the surfactant tails sterically stabilize the synthesized copper particles in solution. Our previous experimental and modeling studies have shown that the strength of the solvent interactions between the bulk liquid organic solvent and the surfactant tails affects the particle growth rate and the mean copper nanoparticle size synthesized within the microemulsion system. The thermophysical properties of compressed liquids and SCFs ...