Studies of nanoparticles from a group of uniform materials based on organic salts (GUMBOS)

Tesfai, Aaron, B.S., B.A., University of Missouri, Columbia, 2003 Doctor of Philosophy, Spring Commencement 2010 Major: Chemistry Studies of Nanoparticles from a Group of Uniform Materials Based on Organic Salts (GUMBOS) Dissertation directed by Professor Isiah M. Warner Pages in dissertation, 101. Words in abstract, 271. Ionic liquids (ILs) are defined as organic salts composed of ions with melting points at or below 100 °C. ILs have gained considerable attention because of their desirable properties such as low volatility, high thermal stability, and tunability. GUMBOS are an emergent class of organic salts, many of which are ionic liquids (ILs). However, some have melting points above 100 °C. The synthesis and characterization of nanoparticles derived from GUMBOS (nanoGUMBOS) is investigated in the first part of this dissertation. NanoGUMBOS are more advantageous than traditional nanoparticles because they possess the inherent desirable characteristics of ILs. In addition to the attractive properties of ILs, nanoGUMBOS can be easily tuned for potential applications by altering the constituent components. The second part of this dissertation investigates the synthesis and characterization of task specific nanoGUMBOS. More specifically, magnetic and fluorescent nanoparticles derived from GUMBOS were investigated in this section. The magnetic nanoGUMBOS were synthesized using an oil-in-water (o/w) emulsion preparation method. These nanoparticles are advantageous because they are uniformly magnetic due to the magnetic functional component built into the nanoparticle. Magnetic nanoGUMBOS synthesized in this section have potential applications in the biomedical field including drug delivery and hyperthermia cancer treatment. Fluorescent nanoGUMBOS were synthesized using different particle fabrication techniques: reprecipitation, o/w emulsion, and a hydrogel preparation method. These particles that are derived from fluorophore based cations are uniformly fluorescent because the GUMBOS synthesized contain the fluorophore. Both fluorescent and magnetic nanoGUMBOS offer many advantages as compared to traditional nanoparticles because their synthetic procedures are rapid, facile, and do not require laborious steps. In addition, these novel fluorescent nanoGUMBOS have potential applications in biomedical imaging

Magnetic and nonmagnetic nanoparticles from a group of uniform materials based on organic salts

The size and uniformity of magnetic nanoparticles developed from a group of uniform materials based on organic salts (GUMBOS) were controlled using an in situ ion exchange, water-in-oil (w/o) microemulsion preparation. Most of these nanoGUMBOS are in fact ionic liquids (i.e., melting points less than 100 °C), while others have melting points above the conventional 100 °C demarcation. Simple variations in the reagent concentrations following a w/o approach allowed us to smoothly and predictably vary nanoparticle dimensions across a significant size regime with excellent uniformity. Average sizesofGUMBOS particles ranging from 14 to 198 nm were achieved by manipulation of the reagent concentration, for example. Controllable formation of this new breed of nanoparticles is important for numerous potential applications and will open up interesting new opportunities in drug delivery, magnetic resonance imaging, and protein separations, among other areas. © 2009 American Chemical Society

Controllable formation of ionic liquid micro- and nanoparticles via a melt-emulsion-quench approach

We present a facile, scalable, and general method for the size-variable generation of monodispersed, near-spherical solid-state (frozen) ionic liquid nanoparticles based on a novel melt-emulsion-quench approach. Simple manipulation of the internal templating droplets within oil-in-water (o/w) microemulsions also permits the formation of well-defined microspheres. This simple and rapid preparation, requiring neither specialized equipment nor harsh conditions, suggests a wealth of potential for these designer nanomaterials within the biomedical, materials, and analytical communities. © 2008 American Chemical Society