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! 100 10-9 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: Discovered 1991, Iijima

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 38.9 o 60.0 o 84.6 o 112.9 o Scale : 200 nm

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 C60 (Fullerene): 1000x better resolution than ink (Xerox) Carbon – graphite C60 (Fullerene): 1000x better resolution than ink (Xerox)

Transistor Vacuum tubes - Nobel prize 1906, Thomson. Emitter Collector                        Vacuum tubes - Nobel prize 1906, Thomson. Emitter Collector Base

Antenna waves

Antennas Dipole, used for raiowaves Nanotube, used for optical waves Radio wave: Dipole, used for raiowaves ~ 3/4 m Nanotube, used for optical waves Optical wave: L

Flat screen displays Field emission

Yarn MWCNT Operational -196oC < T < 450oC Electrical conducting Toughness comparable to Kevlar No rapture in knot

THANK YOU! Nanocarbon Properties Applications Conclusion - 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!