28-10-2010, 11:04 AM
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Space Elevator
Chris Biedrzycki
Ned Cameron
Mike Gruener
Erick Haro
What is a Carbon Nanotube?
Can be thought of as a sheet of graphite (a hexagonal lattice of carbon) rolled into a cylinder.
Why CNTs?
Young's modulus is over 1 Tera Pascal
Strength 100x that of steel at 1/6 the weight (estimated tensile strength is 200 Giga Pascal)
Chemical Vapor Deposition
• Involves heating a catalyst material to high temperatures in a tube furnace and flowing hydrocarbon gas through the tube reactor
• The materials are grown over the catalyst and are collected when the system is cooled to room temperature
• Key parameters are:
– Hydrocarbons
– Catalysts
– Growth Temperature
• CVD process involves the dissociation of hydrocarbon molecules catalyzed by the transition metal, and the dissolution and saturation of carbon atoms in the metal nanoparticle
• Both MWNT and SWNT can be grown by CVD methods
– MWNTs use acetylene gas for the carbon source and a growth temperature between 600 – 800°C
– SWNTs use carbon monoxide or methane for a carbon source and a much higher growth temperature (900 –1200°C)
Space Elevator
Chris Biedrzycki
Ned Cameron
Mike Gruener
Erick Haro
What is a Carbon Nanotube?
Can be thought of as a sheet of graphite (a hexagonal lattice of carbon) rolled into a cylinder.
Why CNTs?
Young's modulus is over 1 Tera Pascal
Strength 100x that of steel at 1/6 the weight (estimated tensile strength is 200 Giga Pascal)
Chemical Vapor Deposition
• Involves heating a catalyst material to high temperatures in a tube furnace and flowing hydrocarbon gas through the tube reactor
• The materials are grown over the catalyst and are collected when the system is cooled to room temperature
• Key parameters are:
– Hydrocarbons
– Catalysts
– Growth Temperature
• CVD process involves the dissociation of hydrocarbon molecules catalyzed by the transition metal, and the dissolution and saturation of carbon atoms in the metal nanoparticle
• Both MWNT and SWNT can be grown by CVD methods
– MWNTs use acetylene gas for the carbon source and a growth temperature between 600 – 800°C
– SWNTs use carbon monoxide or methane for a carbon source and a much higher growth temperature (900 –1200°C)
