Transcript Nanomaterials Chemistry

Chemistry and
Nanomaterials
Carl C. Wamser
Portland State University
Nanomaterials Course - June 27, 2006
Nanoscale = billionths
6 billion people
8000 mile diameter
-9
(10 )
10 billion components
8 inch diameter
Effects of Nanoscale
Structural differences:
Nanoscale Carbon
Bulk Carbon
C60 (Buckeyball)
Smalley, Curl, Kroto
1996 Nobel Prize
Graphite
Diamond
Carbon Nanotubes
Sumio Iijima - 1991
Instrumentation / Imaging
• “Quantum
Corral”
• 48 Fe atoms
positioned by
the STM
used to
image them
http://www.nano.gov/html/facts/home_facts.html
Dimensional Issues
length scale:
nm
µm
ONAMI
mm
m
Chemistry
molecules polymers supramolecular
assemblies
Biology
amino
acids
Electronics
proteins
cells/tissues organisms
semitransistors integrated
conductors
circuits
computers
Chemistry Issues
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Structure / Dynamics / Synthesis
Structure-Function Correlations
Self-Assembled Systems
Applications:
– Materials
– Biological
– Environmental
Organic LEDs
Structure-Function Correlations (emission wavelengths)
Quantum Effects
• Band gap depends on particle size
(number of atoms in the particle)
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
Ionic Bonding
• Molecular 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
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.
Gold Statue
Gold nanoparticles
thiol stabilized gold nanoparticle
melting point: 1337 °K
Jim Hutchison, U. Oregon
http://darkwing.uoregon.edu/~hutchlab
gold nanoparticles (2 nm) in solution
melting point: 650 °K
Covalent Bonding - Carbon
Single-walled
carbon nanotubes:
• armchair - metallic
• zigzag - semiconducting
• chiral - semiconducting
• multi-walled - metallic
Covalent Bonding - Carbon
Carbon nanotubes coated with diamond nanocrystals
M. L. Terranova, et al., Chem. Mater., 17(12) pp 3214 - 3220
Hydrogen Bonding
DNA
Double
Helix
http://www.haveland.com/ 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.
Self-Assembled Monolayer
10 nm
• Monolayer of
DDB on
graphite
(didodecylbenzene)
http://www.nanoscience.com/education/gallery/DDB_ani.htm
Van der Waals Interactions
• SAMMS
Self-Assembled
Monolayers on
Mesoporous
Supports
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
Glen Fryxell, PNNL
http://samms.pnl.gov/
Polyporphyrin Interfacial Film (thin)
Polyporphyrin Interfacial Film (thick)
Photosynthetic Reaction Center
( 1988 Nobel Prize )
http://www.mpibp-frankfurt.mpg.de/~michael.hutter/rcenter.html
Resources
• Nanochemistry references and websites:
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Handbook of Nanotechnology, B. Bhushan, ed. (2004)
Molecular Nanotechnology, D. E. Newton, ed. (2002)
Integrated Chemical Systems, A. J. Bard (1994)
Engines of Creation, K. Eric Drexler (1986)
( http://www.foresight.org/EOC/ )
 “There’s Plenty of Room at the Bottom”, Richard Feynman (1959)
( http://www.zyvex.com/nanotech/feynman.html )
 National Nanotechnology Initiative ( http://www.nano.gov/ )
 Nano Letters - ACS Journal ( http://pubs.acs.org/journals/nalefd/ )
 Materials Today - British journal ( http://www.materialstoday.com )