Chemistry and Nanomaterials

Carl C. WamserPortland State University

Nanomaterials Course - June 27, 2006

Nanoscale = billionths (10-9)

6 billion people8000 mile diameter

10 billion components8 inch diameter

Effects of Nanoscale

Structural differences:

Bulk CarbonNanoscale Carbon

Carbon Nanotubes Sumio Iijima - 1991

C60 (Buckeyball)Smalley, Curl, Kroto

1996 Nobel Prize

Graphite Diamond

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

nm µm mm m

Chemistry

Biology

Electronics

molecules polymers supramolecularassemblies

aminoacids

proteins cells/ tissues organisms

semi-conductors

transistors integratedcircuits

computers

ONAMIlength scale:

Chemistry Issues

• Structure / Dynamics / Synthesis

• Structure-Function Correlations

• Self-Assembled Systems

• Applications:– Materials– Biological– Environmental

Organic LEDs

Structure-Function Correlations (emission wavelengths)

Quantum Effects

Fluorescence of cadmium selenide nanoparticles

4 nm 2 nm

• Band gap depends on particle size(number of atoms in the particle)

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 MalloukPenn 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

melting point: 1337 °K

melting point: 650 °K

Gold Statue Gold nanoparticles

Nanoscale gold has different properties than bulk gold, including: appearance, solubility, and melting point.

thiol stabilized gold nanoparticle

gold nanoparticles (2 nm) in solutionJim Hutchison, U. Oregonhttp://darkwing.uoregon.edu/~hutchlab

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

DNADouble 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

• Monolayer of DDB on graphite

(didodecylbenzene)

http://www.nanoscience.com/education/gallery/DDB_ani.htm

10 nm

Van der Waals Interactions

• SAMMSSelf-Assembled Monolayers on Mesoporous Supports

Glen Fryxell, PNNL

QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.

http://samms.pnl.gov/

Polyporphyrin Interfacial Film (thin)

Polyporphyrin Interfacial Film (thick)

Photosynthetic Reaction Center

http://www.mpibp-frankfurt.mpg.de/~michael.hutter/rcenter.html

( 1988 Nobel Prize )( 1988 Nobel Prize )

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)

( 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 )