Nano overview bottom up approach WAMSER

Chemistry and
Nanomaterials
Carl C. Wamser
Portland State University

Nanomaterials Course - June 27, 2006


Nanoscale = billionths (10-9)

6 billion people
8000 mile diameter

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

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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
•
•
•
•

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

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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
/>
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

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)

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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
/>


Polyporphyrin Interfacial Film (thin)


Polyporphyrin Interfacial Film (thick)

Photosynthetic Reaction Center
( 1988 Nobel Prize )

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Resources
• Nanochemistry references and websites:





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)
( )
 “There’s Plenty of Room at the Bottom”, Richard Feynman (1959)
( )
 National Nanotechnology Initiative ( )
 Nano Letters - ACS Journal ( )
 Materials Today - British journal ( )