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Special Focus: Carbon Nanostructures

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Presentation on theme: "Special Focus: Carbon Nanostructures"— Presentation transcript:

1 Special Focus: Carbon Nanostructures

2 Carbon Nanostructures
Buckyballs Nanotubes SWNT & MWNT (single-walled nanotubes & multi-walled nanotubes) Graphene thin layers

3 Carbon Nanostructures
Metallic conductor (graphite) Variety of properties Insulating Polymer (hydrocarbon chains) Semiconductor (diamond) 3-D Variety of structures 2-D 1-D 0-D

4 Carbon Fullerenes 0-dimensional carbon structure
Usually C60, but also refers to C70, C76, Cn (n > 60) Every carbon site on C60 is equivalent Bonded to three other carbons average bond is 1.44 Å (C-C is 1.46 Å; C=C is 1.40 Å) 20 hexagonal faces; 12 pentagonal faces Diameter: Å (7.1 x m)

5 Buckminster Fuller (1895-1983):
Architect, engineer, inventor; Developed the geodesic dome

6 Epcot Center in Disneyworld

7 Climatron at the Missouri Botanical Garden

8 Biosphere Museum in Canada

9 The shape of the geodesic dome encloses the greatest volume while taking up the least surface area.
Fuller hoped the design would produce large numbers of inexpensive homes for soldiers returning from WWII. The building can withstand high winds such as those found in hurricanes.

10 Synthesis of Fullerenes
Laser ablation (vaporizing graphite with a laser) Plasma arcing of graphite or coal Fullerenes found in the soot e- C+ Anode Cathode Nanotube deposit Combustion synthesis Burn hydrocarbon at low pressure

11 Demo: Laser Pointer, watch plate, Charcoal briquette!

12 Single-Walled Carbon Nanotubes (SWCNT; SWNT)
Multi-Walled Carbon Nanotubes (MWCNT; MWNT) How to make them: Arc evaporation (plasma arcing) Laser ablation PECVD (plasma-enhanced chemical vapor deposition) Electrochemical methods

13 Carbon Nanotubes Armchair (b) Zigzag (c) Chiral

14 Properties of Carbon Nanotubes
Mechanical Stiff and robust structures C-C bonds in graphite (and nanotubes) is the one of the strongest bonds in nature Flexible; do not break when bent Conductivity Extremely high thermal conductivity Extremely high electrical conductivity Potential Applications: catalysis - hydrogen storage - biological cell electrodes resistors - flow sensors - electron field emission tips electronic/mechanical devices - scanning probe tips

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16 Carbon Nanotube Applications: NEMS: Nanoelectricalmechanical systems
“Nantero is a nanotechnology company using carbon nanotubes for the development of next-generation semiconductor devices... In the field of memory, Nantero is developing NRAM™, a high-density nonvolatile Random Access Memory.” Gold plate ~ (100 nm)2 attached to outer shell of suspended MWCNT (on Si wafer) “electrostatically rotate the outer shell relative to the inner core”

17 WATCH CLIP FROM “NOVA: Making Things Stronger” about Carbon Nanotubes (Scene Selection)


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