(3cd) Well Defined Nanomaterials Through Tunable and Smart Solvents

The production of large quantities of monodisperse nanoparticles with unique properties remains a non-trivial task and is one hurdle to the wide use of nanoparticles in many applications.  Nanomaterials have shown the potential to revolutionize catalysis, energy production, drug delivery, and composite materials.  This potential is greatly increased if facile synthesis, processing, and modeling techniques are developed. Routes to produce large quantities of well-defined nanomaterials and leveraging their unique properties can be enabled through the use of smart solvent technology, sustainable engineering, and computational modeling.

My PhD work, performed at Auburn University under the supervision of Christopher B. Roberts, focused on the manipulation and prediction of the size distribution of metallic nanoparticles dispersed in various tunable solvent systems (i.e., CO₂-gas expanded liquids).  Through a fine control in various system variables (including applied gas pressures, surface chemistry, and solvent conditions) I demonstrated a high degree of control over the size distribution of nanoparticles that can be dispersed or precipitated in a solvent.  For example, a polydisperse (±2 nm) sample of dodecanethiol-stabilized gold nanoparticles dispersed in a mixture of hexane and acetone can be size-selectively fractionated into multiple monodisperse (±0.5nm) samples in a single processing stage without producing any waste.  Also, I have developed a Total Interaction Energy Model that is capable of predicting the size distribution of nanoparticles that can be dispersed at various solvent conditions.  My work at Auburn University demonstrated that tunable solvents and basic thermodynamics are one potential route to developing and understanding new nanoparticle processing techniques.

My postdoctoral work, performed at Georgia Tech under the supervision of Charles L. Liotta and Charles A. Eckert, focused on employing smart solvent technologies (e.g., reversible ionic liquids and organic-aqueous tunable solvents) and fundamental chemistry to improve and understand different processes (e.g., catalyst recovery/recycle and polymer degradation/stabilization).  For example, we have developed a technique to synthesize metallic nanoparticles using a reversible ionic liquid (an ionic liquid capable of “switching” its ionic character on or off when exposed to the proper stimulus) with the potential to produce zero waste.  Using various techniques (e.g., TEM, DLS, micro-structure analysis), we have developed a theory that describes the synthesis mechanism and have leveraged it to optimize the synthesis to provide monodispersed nanoparticles.

The work I have conducted during my PhD and postdoctoral fellowship, which will be presented in this poster, demonstrate that smart and tunable solvent technologies, sustainable engineering, and computational thermodynamic modeling enable novel methods of producing large quantities of monodispersed nanoparticle needed for many applications.