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!