Gold Statue
Gold nanoparticles
thiol stabilized gold nanoparticle
melting point: 1337 °K
Jim Hutchison, U. Oregon
/~hutchlab
gold nanoparticles (2 nm) in solution melting point: 650 °K
Covalent Bonding - Carbon
Carbon nanotubes coated with diamond nanocrystals
M. L. Terranova, et al., Chem. Mater., 17(12) pp 3214 - 3220
Hydrogen Bonding
Ionic / Electrostatic Effects
• Conformational Molecular Rectifiers, A. Troisi and M. A. Ratner, Nano Lett., 4(4), 591-595 (2004).
Metallic Bonding
Nanoscale gold has different properties than bulk gold, including: appearance, solubility, and melting point.
4 nm
2 nm
Fluorescence of cadmium selenide nanoparticles
Chemical Bonding
• Forces used to assemble structure:
– Ionic – Metallic – Covalent – H-bonding – Metal-ligand – Van der Waals – π-π stacking
Covalent Bonding - Carbon
Single-walled carbon nanotubes:
• armchair - metallic • zigzag - semiconducting • chiral - semiconducting • multi-walled - metaecular beaker epitaxy
• Layer-by-layer growth of polyelectrolytes
• Tom Mallouk Penn State U
http://www.mapr.ucl.ac.be/~jonas/Home_page_AJ/Research/ESA/ESA.html
Ionic / Electrostatic Effects
• A molecular elevator
• Responsive to acid/base
• J. D. Badjic, et al., Accts. Chem. Res., in press.
• J.F. Stoddart, UCLA
Chemistry and Nanomaterials
Carl C. Wamser Portland State University
Nanomaterials Course - June 27, 2006
Nanoscale = billionths (10-9)
6 billion people 10 billion components
Self-Assembled Monolayer
10 nm
• Monolayer of DDB on graphite
(didodecylbenzene)
/education/gallery/DDB_ani.htm
8000 mile diameter
8 inch diameter
Effects of Nanoscale
Structural differences:
Bulk Carbon
Nanoscale Carbon
Graphite
Diamond
C60 (Buckeyball) Smalley, Curl, Kroto
DNA Double Helix
/ graphics/dna-3d.jpg
π-π Stacking - Liquid Crystals
Charge-Trapping Memory Device
Liu, C-Y.; Bard, A.J.; Acc. Chem. Res. (1999), 32, 235-234.
/html/facts/home_facts.html
Dimensional Issues
M a c in to s h P IC T im a g e fo rm a t
is n o t s u p p o rte d
Chemistry Issues
• Structure / Dynamics / Synthesis • Structure-Function Correlations • Self-Assembled Systems • Applications:
1996 Nobel Prize
Carbon Nanotubes Sumio Iijima - 1991
Instrumentation / Imaging
• “Quantum Corral”
• 48 Fe atoms positioned by the STM used to image them
– Materials – Biological – Environmental
Organic LEDs
Structure-Function Correlations (emission wavelengths)
Quantum Effects
• Band gap depends on particle size (number of atoms in the particle)