Transcript Nano-Technology

Nano-Technology
Lee Zi Jing
3i3 (13)
What is nano-technology?
• Nano-technology is the study of matter at an atomic
scale
• It generally deals with materials from 1 to 100 nano
meters in size
• Nano-technology involves a diverse range of research.
• In this presentation, we will be examining the uses of
nano carbon.
The nano scale
• One nanometer (nm) is one billionth, or 10−9, of a meter.
• A nanometer to a meter is marble to the size of the earth.
• In the time a man takes to raise the razor the shave his
beard, it has grown by a nano meter!
10-9
10-6
10-3
100
103
106
109
Carbon
•
Melting point: ~ 3500oC
• Atomic radius: 0.077 nm
•
Basis in all organic componds
•
10 mill. carbon componds
Bonding of Carbon
Graphite
Diamond
Bonding in nano carbon
Nano carbon - Materials
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Fullerene
Tubes
Cones
Carbon black
Horns
Rods
Foams
Nanodiamonds
Fullerene
• A fullerene is any molecule composed entirely of
carbon, in the form of a hollow sphere, ellipsoid or tube.
”The most symmetrical large molecule”
• Discovered in 1985
- Nobel prize Chemistry 1996, Curl, Kroto, and Smalley
• C60, 70, 76 and 84.
~1 nm
Fullerene Properties
• Symmetric shape
→ lubricant
• Large surface area
→ catalyst
• High temperature (~500oC)
• High pressure
• Hollow
→ caging particles
Fullerene Properties
• Chemically stable as graphite
- most reactive at pentagons
• Crystal by weak van der Waals
force
• Superconductivity
- K3C60: 19.2 K
- RbCs2C60: 33 K
Tubes
• Discovered 1991, Iijima
Roll-up vector:


Ch  n a1  m a2
Tube Properties

Carbon nanotubes are very flexible
Cones
• Discovered 1994 (closed form) Ge & Sattler
1997 (open form) Ebbesen et al.
• Closed: same shape as HIV capsid
• Possible scale-up production (open form)
• Used for hydrogen storage
Nano carbon cones at various angles of opening
19.2 o
Scale : 200 nm
38.9 o
60.0 o
84.6 o
112.9 o
Carbon Black
Large industry
- millions of tons per year
• Tires, black pigments, plastics,
dry-cell batteries, UV-protection
etc.
• Size: 10 – 400 nm
Applications of nano carbon materials
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Writing
Transistor
Antenna
Flat Screen Displays
Yarn
Writing
Carbon – graphite
C60 (Fullerene): 1000x better
resolution than ink (Xerox)
Transistor
• Vacuum tubes
- Nobel prize 1906,
Thomson.
Emitter
Collector
Base
Antenna waves
Antennas
• Dipole, used
for raiowaves
Radio wave:
~ 3/4 m
m
3 10
c
s ~ 100 MHz
f  

3m
8
• Nanotube,
used for
optical waves
Optical wave:
L
 ~ L / 2 ~ 500 nm
Flat screen displays
• Field emission
Yarn
MWCNT
• Operational -196oC < T < 450oC
• Electrical conducting
• Toughness comparable to Kevlar
• No rapture in knot
Conclusion
• Nanocarbon
- fullerene
- ”most symmetrical”
- tubes
- ”strongest”
- cones
- ”one of the sharpest”
- carbon black - ”large production”
• Properties
- electrical, mechanical, thermal, storage, caging
• Applications
- antenna, writing, transistor, yarn, flat screen
displays
THANK
YOU!