| Room temperature ionic liquids have been receiving attention as alternatives to traditional organic solvents. In particular, 1,3-dialkylimidazolium ionic liquids are attractive because their properties are easily tailored by altering the counteranion and type of alkyl chains on the imidazolium ring. Ionic liquids are finding use as dual-function solvents and stabilizing agents for nanoparticles. They are able to solvate a wide variety of species and are thought to consist of polar and non-polar domains of hydrogen bonded networks, which may be able to stabilize and even template nanoparticle growth. They have several other properties (e.g., nonflammability, nonvolatility, recyclability) that potentially make them more environmentally sound compared to some traditional organic solvents. We have developed different microfluidic architectures for the synthesis of gold and silver nanoparticles in ionic liquid flows. The large surface area-to-volume ratio within microscale channels allows for improved heat and mass transport and more homogeneous reaction conditions, leading to monodisperse nanoparticle products. Additionally, microfluidic syntheses allow for finer control over reaction parameters compared to traditional batch reactions. Herein, we examined the combined beneficial effects of ionic liquid flows and different microfluidic systems to prepare gold and silver nanoparticles that are more monodisperse than those produced in analogous batch reactions. The compatibility of ionic liquids with inexpensive polydimethylsiloxane microfluidic devices makes it a unique system for the reproducible synthesis of high-quality nanoparticles. |
