140 likes | 282 Views
Measuring the Solubility of Ligated Gold Nanoparticles in Hydrocarbon Solvents. By Jeffrey Powell Physics REU Summer 2009 Partially Funded Through NSF. Nanotechnology. Reside at the edge of quantum mechanics and condensed matter Can act and behave as a “supermolecule”
E N D
Measuring the Solubility of Ligated Gold Nanoparticles in Hydrocarbon Solvents By Jeffrey Powell Physics REU Summer 2009 Partially Funded Through NSF
Nanotechnology • Reside at the edge of quantum mechanics and condensed matter • Can act and behave as a “supermolecule” • Large ratio of surface area to volume • Tip of the Iceberg
Synthesis of Gold Nanoparticles • Inverse Micelle Method-Soaps and Salts • Reduction of Gold Salt to grow nanocrystals • Ligands added to stabilize • Micellar Diffusion structures nanocrystals
Digestive Ripening • Reflux solution of polydisperse particles • Forms monodisperse solution Post Digestive Ripening Pre Digestive Ripening
Alkane Ligated Gold Particle Au Au3850(C12SH)350
Solubility Tests • Dissolved in alkane solvents • Centrifuge at 12000g acceleration • Take UV-Vis absorbance data on the supernatant • Raw data converted into concentration of gold in solution
“Like Dissolves Like” • Thiol chain length influences solubility • Gold concentration peaks where solvent similar to ligand
“Like Does Not ALWAYS Dissolve Like” • Peaks not where expected • Unknown forces at work
Struggles • Separation of two-phase system • Melting point of hexadecane thiol • Stability of particles
Conclusion • Suspension of particles acting as a thermal reversible solution • Future Work