Nano-Technology Lee Zi Jing 3i3 (13). What is nano-technology? Nano-technology is the study of...
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Transcript of Nano-Technology Lee Zi Jing 3i3 (13). What is nano-technology? Nano-technology is the study of...
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!
10010-9 10-6 10-3 103 106 109
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
• 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
Roll-up vector:
21 amanCh
• Discovered 1991, Iijima
Tube Properties
Carbon nanotubes are very flexible
Cones
Scale : 200 nm
19.2 o38.9 o 60.0 o 84.6 o 112.9 o
• 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
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
• Writing• Transistor• Antenna• Flat Screen Displays• Yarn
Writing
Carbon – graphite C60 (Fullerene): 1000x better resolution than ink (Xerox)
Transistor
Base
CollectorEmitter
• Vacuum tubes - Nobel prize 1906,
Thomson.
Antenna waves
Antennas
• Dipole, used for raiowaves
~ 3/4 m
• Nanotube, used for optical waves
MHzm
sm
cf 100~
3
103 8
Radio wave:
Optical wave: L
nmL 500~2/~
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!