(158f) Synthesis of Nanoparticles Through the Use of Reversible Ionic Liquids

Many methods of nanoparticle synthesis are cost, energy and time intensive and methods that have the potential to overcome these hurdles garner wide interest.  A facile nanoparticle synthesis technique with the potential to produce zero waste is possible through the use of reversible ionic liquids (ionic liquids that are capable of switching their ionic nature on or off through the use of an external stimulus).  The RevILs discussed herein are formed when CO₂ is introduced to a silylamine (e.g., 3-(aminopropyl) triethylsilane) to form an ammonium-carbamate ion pair.  These RevILs can be returned to their original molecular (i.e., non-ionic) form when heated or sparged with an inert gas.  Through adjustments in the structure of the silylamine and the degree of conversion of the molecular form to the ionic form the properties (e.g., viscosity, density, polarity, etc.) of the solvent medium can be drastically tuned.  Nanoparticles with relatively narrow size distribution and an average size less than 10 nm can be produced using these RevILs in a process akin to a reverse-micelle synthesis with the ability to recycle the RevIL.  Methods of nanoparticle synthesis and deposition onto a support will be discussed.