Chem 570:
Nanotechnology for
Teachers
Dr. John S. Hutchinson
Professor of Chemistry
Director of Education, CBEN
Dr. Carolyn Nichol
Associate Director of Education,
CBEN
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What is Nanotechnology?
Nanotechnology is the creation of functional materials,
devices, and systems through control of matter on the
nanometer length scale, exploiting novel phenomena and
properties (physical, chemical, biological) present only at that
length scale.
“If I were asked for an area of science and engineering that will most likely
produce the breakthroughs of tomorrow, I would point to nanoscale science and
engineering.”
Neal Lane
University Professor, Rice University
Former NSF Director
Assistant to President Clinton for Science and Technology
What is Nanotechnology?
Nanotechnology is the creation of functional materials,
devices, and systems through control of matter on the
nanometer length scale, exploiting novel phenomena and
properties (physical, chemical, biological) present only at that
length scale.
• What is the “nanometer length scale?”
• What “novel phenomena” are present on the nanoscale?
• How could we “control matter” on the nanoscale?
And, importantly
• Why is this all so exciting?
What isn’t Nanotechnology?
Molecular Engineering?
Science Fiction!
Nanobots?
“Nano”: How small is that, really?
Mountain
1 km
1000 m
0.001 km = 1 m
Child
1m
Ant
1 mm
0.001 m
1,000 mm = 1 m
Bacteria
1 μm
0.000001 m
Sugar Molecule
1 nm
0.000000001 m
1,000,000 μm = 1 m
1,000,000,000 nm = 1 m
Orders of Magnitude: 1 nm = 10-9 m
Powers of 10 video
1 Carbon atom radius = 77.2 pm = 77.2×10-12 m=0.077nm
Carbon-Carbon bond length = 154 pm = 0.154 nm
Sugar Molecule
1 nm
0.000000001 m
1,000,000,000 nm = 1 m
Atomic Structure: Quick Overview
„
„
Nucleus
„
radius ~10-15m = 10-6nm
„
Positive charge = atomic number
Electron cloud
„
Radius ~10-10m = 0.10nm
„
Number of electrons = atomic number
„
Electrons arranged in “shells”
Molecular Structure: Quick Overview
„
Structure / Geometry
„
Bonding
-
Ionic bonding
-
Covalent bonding
-
Bond energy = energy required to break bond
Carbon Nanoparticles
„
C60
„
„
buckminsterfullerene
1985 Richard
Smalley, Robert Curl,
Harold Kroto
„
12 pentagons
„
20 hexagons
„
elongated fullerenes
C60
C70
C80
Rolling up Graphene to make a SWNT
taken from
http://www.photon.t.u-tokyo.ac.jp/~maruyama/wrapping.files/frame.html
Single-Walled Carbon Nanotubes
Importance of Scale
„
„
„
At the micron (1,000
nm) and larger scale,
classical physics
determines properties.
At the Angstrom (0.1
nm) scale, quantum
mechanics determines
properties.
At the nanometer scale,
fundamental properties
depend on exactly how
big the particle is.
Classical Mechanics
(Everyday Physics)
Quantum Mechanics
(Wave Physics)
0.1
1
10
100
Length Scale (nm)
The nanoworld
1000
Quantum Mechanics vs. Classical
Mechanics
„
Continuous vs Quantized Energy
„
Separation of Energies depends on Size
Energy vs. Size applet
Size Matters
Bulk Gold = Yellow
Nanogold = Red
Metal Nanoshells
20nm
Quantum Mechanics vs. Classical
Mechanics
„
Wave motion vs trajectory motion
„
Uncertainty Principle
Two slit interference experiment
Surface Area versus Volume
„
„
„
„
„
Nanosized particles dramatically increase
surface area
Compare fixed volumes, different size
particles:
1 particle, R = 1m, V = 4/3 π, S = 4π
1000 particles, R = 0.1m, V = 4/3 π,
S = 40π
1027 particles, R = 10-9m, V = 4/3 π,
S = 4•109π
Tools of the Nanoscale
„
Electron Microscopy
„
„
Scanning Tunneling Microscopy
„
„
(SEM, TEM)
(STM)
Atomic Force Microscopy
„
(AFM)
The Light Microscope
http://micro.magnet.fsu.edu/primer/anatomy/
Timeline of Microscopy
c. 1625
1938
SEM AFM
1981 1986
http://www.nobel.se/physics/educational/microscopes/powerline/index.html
Optical vs. Electron Microscopy
Radiolarian (amoeboid protozoa)
Optical microscopy image
Electron microscopy image
Why do electron beams give superior resolution to
light rays?
Shorter wavelength!
Scanning Electron Microscopy
http://mse.iastate.edu/microscopy/whatsem.html
http://mse.iastate.edu/microscopy/path2.html
http://www.mos.org/sln/sem/seminfo.html
Transmission Electron Microscopy
http://www.nobel.se/physics/educational/microscopes/tem/index.html
CdSe quantum dot, Colvin
300 nm
Hollow colloidal ellipses, Colvin
Scanning Tunneling Microscopy
ProbeSimulator.exe
STM Probe Simulator
http://www.nobel.se/physics/educational/microscopes/scanning/index.html
STM: Manipulating Atoms
Iron atoms on Copper surface
http://www.almaden.ibm.com/vis/stm/corral.html
Atomic Force Microscopy
AFM Simulator
What Nanomaterials Can Do
„
Optical Properties
„
„
„
„
„
Photochemistry
Absorption/scattering
/ fluorescence, or
lack thereof
Mechanical
Properties
Electrical/Thermal
Properties
„
„
Nanoscale Control
„
Porosity
„
Coatings
Self-Assembly
„
Strength
„
„
Modulus
„
Multifunctionality
Conductivity
Directed SelfAssembly
Types of Nanomaterials
Carbon Allotropes
Gold Nanoparticles
Silica Colloids
2 μm
Fluorescence image of a free SWNT in water suspension
Real time
Nanotube length = 10 μm
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