Carbon nanotube

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  • 1. BY: INDRANEEL MAJUMDAR & ANJANI KUMAR (5th SEMESTER, MECHANICAL ENGG,PCE RKL).
  • 2.  Introduction  Discovery  Carbon Nanotubes (CNTs)  Types  Methods of synthesis  Properties  Applications  Obstacles  Conclusion  Reference
  • 3. Carbon nanotube (CNTS) were first discovered in 1991 by the Japanese electron microscopist Sumio Iijima who was studying the material deposited on the cathode during the arc-evaporation synthesis of fullerenes.
  • 4.  Carbon nanotubes (CNTs) are carbon allotropes  Its nanoscopic in structure and in the shape of a hollow cylinder  cylinders closed both ends by semi-fullerene structures.  diameter as small as 1nm  can have one “layer” or wall (single walled nanotube)  more than one wall (multi walled nanotube).
  • 5. Armchair (n,m) = (5,5) = 30 Zig Zag (n,m) = (9,0) = 0 Helical (n,m) = (10,5) 0 < < 30
  • 6.  Single walled  Multi walled
  • 7.  Connect two graphite rods to a power supply, place them millimeters apart, and throw switch. At 100 amps, carbon vaporizes in a hot plasma.  Can produce SWNT and MWNTs with few structural defects  Tubes tend to be short with random sizes and directions
  • 8.  Place substrate in oven, heat to 600 C, and slowly add a carbon-bearing gas such as methane. As gas decomposes it frees up carbon atoms, which recombine in the form of CNTs  Easiest to scale to industrial production; long length
  • 9.  Blast graphite with intense laser pulses; use the laser pulses rather than electricity to generate carbon gas from which the CNTs form; try various conditions until hit on one that produces prodigious amounts of SWNTs
  • 10.  Extremely high Young’s modulus  200x stronger than steel of the same diameter  The first synthetic material to have greater strength than spider silk  Excellent conductors of electricity and heat
  • 11. The strength of the carbon-carbon bonds gives carbon nanotubes amazing mechanical properties. The Young's modulus of the best nanotubes can be as high as 1000 GPa which is approximately 5x higher than steel. The tensile strength, or breaking strain of nanotubes can be up to 63 GPa, around 50x higher than steel.
  • 12.  CNTs very good thermal conductors along the tube, exhibiting a property known as "ballistic conduction", but good insulators laterally to the tube axis. Measurements show that a SWNT has a room-temperature thermal conductivity along its axis of about 3500 W·m−1·K−1 compare this to copper, a metal well known for its good thermal conductivity, which transmits 385 W·m−1·K−1.
  • 13.  Because of the symmetry and unique electronic structure of graphene, the structure of a nanotube strongly affects its electrical properties. metallic nanotubes can carry an electric current density of 4 × 109 A/cm2, which is more than 1,000 times greater than those of metals such as copper.
  • 14. ++++++ + no +++++ no Conducts electricity ++++++++++Buckyballs ++++++++++++++++Carbon Nanotubes +++Not known+++++Diamond +++++++++Graphite +++Coal Conducts heat Tensile strengthHardnessAllotrope
  • 15. Water filters Bullet proof vest
  • 16.  Lack of vision to identify those aspects that could be changed through its use.  Lack of skilled personnel.  Level of Investment.
  • 17. Their mechanical properties, and unique electronic properties make them both interesting & useful in future technologies, but growth mechanisms yet to be fully established.
  • 18.  http://www.ipt.arc.nasa.gov  http://www.mknano.com  www.nanohub.org  www.wikipedia.com  Carbon nanotubes science and applications BY M.Meyyapan