Carbon Nanotubes Nanotubes Carbon A New New Era Era A By By - PowerPoint PPT Presentation

Low Dimensional System & Nanostructures Angel Rubio & Nerea Zabala Carbon Nanotubes Nanotubes Carbon A New New Era Era A By By Afaf El El- -Sayed Sayed Afaf 2009 2009

Outline Outline World of of Carbon Carbon World - Graphite Graphite - - Diamond Diamond - - Fullerene Fullerene - Carbon Nanotubes Nanotubes CNTs CNTs Carbon - Discovery Discovery of of CNTs CNTs - - Basic Basic Structure Structure & & Types Types of of Nanotubes Nanotubes - - Electronic Electronic Structure Structure of of CNTs CNTs - Properties & & Applications Applications of of CNTs CNTs Properties

World of of Carbon Carbon World sp sp 2 s p 3

Graphite & Diamond 2 orbital In graphite, The sp In graphite, The sp 2 orbital In diamond, each In diamond, each form the strong σ σ - -bonds bonds form the strong carbon atom has four carbon atom has four between carbon atoms in between carbon atoms in nearest neighbors. nearest neighbors. the graphite planes, while the graphite planes, while 3 orbital form The sp sp 3 orbital form The the p p z , or π π , orbital provide , orbital provide the z , or the strong σ σ - -bonds bonds the strong the weak Van der the weak Van der waals waals between carbon between carbon bonds between the bonds between the atoms. atoms. planes. planes.

Fullerene Fullerene In the C In the C 60 60 molecule, the carbon atoms are molecule, the carbon atoms are bonded in a structure made up of 20 bonded in a structure made up of 20 hexagons and hexagons and 12 pentagons 12 pentagons. Each of the . Each of the carbon atoms in C 60 carbon atoms in C 60 is joined to three is joined to three neighbors, so the bonding is the bonding is neighbors, so the bonding is the bonding is essentially sp essentially sp 2 2 , although there may be a , although there may be a 3 character due to the small a mount of sp small a mount of sp 3 character due to the curvature. curvature . The carbon 60 atoms are bonded The carbon 60 atoms are bonded together in an array of hexagons and together in an array of hexagons and pentagons, like a soccer ball. These pentagons, like a soccer ball. These molecules are called Buckminster molecules are called Buckminster fullerenes in honor of Buckminster Fuller fullerenes in honor of Buckminster Fuller who first designed similarly shaped who first designed similarly shaped geodesic domes. geodesic domes.

Carbon Nanotubes Carbon Nanotubes

Discovery of CNTs CNTs Discovery of Since the early 1960s 1960s, , Harry Harry Kroto Kroto, of the , of the University of Sussex , had been Since the early University of Sussex , had been fascinated in the processes occurring on the surfaces of stars, and and fascinated in the processes occurring on the surfaces of stars, believed that experiments on the vaporization of graphite might provide key provide key believed that experiments on the vaporization of graphite might insights into these processes. insights into these processes. On the other hand, Richard Smalley Richard Smalley, of , of Rice University , Houston, had On the other hand, Rice University , Houston, had different reasons for being interested in what might happen when one one different reasons for being interested in what might happen when vaporizes carbon. vaporizes carbon. In August 1985 1985, the two scientists began the now famous series of , the two scientists began the now famous series of In August experiments on the vaporization of graphite vaporization of graphite. They were immediately struck . They were immediately struck experiments on the by the formation of C C 60 . The discovery of C 60 , published in nature in by the formation of 60 . The discovery of C 60 , published in nature in November 1985, had an impact which extended way beyond the confines November 1985, had an impact which extended way beyond the confi nes of academic chemical physics, and marked the beginning of a new era in era in of academic chemical physics, and marked the beginning of a new carbon science. carbon science. Perhaps, Carbon nanotubes Carbon nanotubes are the most important fruits of this research. are the most important fruits of this research. Perhaps, Discovered by the electron microscopist microscopist Sumio Sumio Iijima Iijima, of the , of the NEC Discovered by the electron NEC laboratories in Japan, in in Japan, in 1991 1991, these , these ‘ ‘molecular carbon fibers molecular carbon fibers’ ’ consist of consist of laboratories tiny cylinders of graphite, closed at each end with caps which contain ontain tiny cylinders of graphite, closed at each end with caps which c precisely six pentagonal rings. precisely six pentagonal rings.

ϕ Basic Structure & Types of Types of CNTs CNTs Basic Structure & ϕ = + R na ma 1 2 0 ≤ | m | ≤ n & Φ <30 o

SWNTs, MWNTs and!!!!! Neural Tree

Electronic Structure Structure of of Graphene Graphene Electronic “Zero-bandgap Semiconductor” Unit cell π * anti-bonding orbitals π bonding orbitals Brillouin Zone

Graphene to SWNT = + = + C h na ma T t a t a 1 2 1 1 2 2 ( ) r r 1 = − + K t b t b 1 2 1 1 2 N ( ) r r 1 = − K m b n b 2 1 2 N

Different Properties of CNTs Properties Nanotubes By Comparison Estimated at 1 X 10 10 9 9 A/cm A/cm 2 2 Copper wires burn burn out at out at Estimated at 1 X Copper wires Current carrying capacity 6 A/cm for MWCNT: 20 20 – – 50 nm 50 nm about 1X 10 10 6 A/cm 2 2 for MWCNT: about 1X Can activate phosphors at Molybdenum tips require Can activate phosphors at Molybdenum tips require Field Emission 1– – 3 3 volts if electrodes are volts if electrodes are fields of 50 50 – – 100 100 V/m and V/m and 1 fields of spaced 1 micron 1 micron apart apart have very limited lifetimes spaced have very limited lifetimes Predicted to be as high as Nearly pure diamond Predicted to be as high as Nearly pure diamond Heat Transmission 6,000 W/ W/m.K m.K at room at room transmits heat at 3,320 3,320 6,000 transmits heat at temperature temperature W/ W/m.K m.K Stable up to 2,800 2,800 o o C C in in Metal wires in microchips Stable up to Metal wires in microchips Temperature Stability vacuum, 750 750 o o C C in air in air melt at 600 600 – – 1,000 1,000 o o C C vacuum, melt at 3 GPa Elastic modulus ~ Elastic modulus ~ 10 10 3 GPa ~ 200 ~ 200 GPa GPa for steel for steel Elasticity Yield Strength ~ Yield Strength ~ 65 65 GPa GPa ~ 0.8 ~ 0.8 GPa GPa for steel for steel

Applications of CNTs Glucose sensors CNT-FETs CNT scanning tip CNT-Solar Cells CNT- Flexible Displays CNT interconnects Neural Tree

Future!!!!!! Space Elevator Space Platform Faster, Better and Cheaper Space Aircrafts

Conclusion A new era has begun of Carbon Nano-Science!!! We should think of our needs?!!!

Bibliographic Search R. Saito, et.al, “Physical Propertiest of Carbon Nanotubes”, Imperial College Press, 1998. Peter Morgan, “Carbon Fibers and their composites”, CRC press, 2005. Michael J.O’Connell, “Carbon Nanotubes: Properties and Applications”, CRC press, 2006. Charles Kittle, “Introduction to Solid State Physics”, John Wiley & Sons, Inc., 8th Edition, 2005. Karl M. Kadish and Rodney S.Ruoff, “Fullerenes: Chemistry, Physics and Technology”, Wiley- IEEE, 2000. Peter J.F. Harris, "Carbon Nanotubes and Related Structure: New Materials for the Twenty First Century", Cambridge University Press, 1999. The nanotube Sites: http://nanotube.msu.edu/ http://www.pa.msu.edu/cmp/csc/nanotube.html http://cobweb.ecn.purdue.edu/~mdasilva/Structure.shtml A. Appenzeller, E. Joselevich, W. Honlein, “Carbon Nanotubes for Data Processing,” in R. Waser, “Nanoelectronics and Information Technology,” Wiley- VCH (2003). A. Adams, "Physical Properties of Carbon Nanotubes", as a part of the honours chemistry research project, 2000. http://www.pa.msu.edu/cmp/csc/ntproperties/electricaltransport.html Thomas A. Adams, "Physical Properties of Carbon Nanotubes", as a part of the honours chemistry research project, 2000. http://www.pa.msu.edu/cmp/csc/ntproperties/opticalproperties.html J. Hone, " Carbon Nanotubes: Thermal Properties", Dekker Encyclopedia of Nanoscience and Nanotechnology, 2004. D. Yokoyama et al., Appl. Phys. Lett., 91, 263101, 2007. Christina Guice, Henry C. Foley, Head and Robb Chair and Bo Yi, "Dynamics of Nanotube Synthesis", McNair Scholar, Pennsylvania State University, 2003. http://www.nanowerk.com/nanotechnology/introduction/introduction_to_nanotechnology_23.html NASA web site; http://www.nasa.gov/vision/space/gettingtospace/16sep_rightstuff_prt.htm NASA web site; http://science.nasa.gov/headlines/y2000/ast07sep_1.htm SPACE.com -- Russians Plan New Space Platform. http://www.space.com/businesstechnology/080115-technov-russia-platform.html http://en.wikipedia.org/wiki/Potential_applications_of_carbon_nanotubes