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Wedn. cnt ppt

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Wedn. cnt ppt

  1. 1. CARBON NANOTUBES By: HIMANSHU TYAGI CARBON NANOTUBES BY: HIMANSHUTYAGI ECE- 3rdYEAR Roll No. : 1122231032
  2. 2. What are carbon nanotubes 2 CNT: Rolling-up a graphene sheet to form a tube Schematic of a CNT
  3. 3. DID YOU KNOW?  Carbon nanotubes, composed of interlocking carbon atoms, are 1000x thinner than an average human hair – but can be 200x stronger than steel.
  4. 4. #1952 Radushkevich and Lukyanovich publish a paper in the Soviet Journal of Physical Chemistry showing hollow graphitic carbon fibers that are 50 nanometers in diameter. #1979 John Abrahamson presented evidence of carbon nanotubes at the 14th Biennial Conference of Carbon at Pennsylvania State University. #1981 A group of Soviet scientists published the results of chemical and structural characterization of carbon nanoparticles produced by a thermocatalytical disproportionation of carbon monoxide. #1991 Nanotubes discovered in the soot of arc discharge at NEC, by Japanese researcher Sumio Iijima.
  5. 5. Types of CNTs  Single Wall CNT (SWCNT)  Multiple Wall CNT (MWCNT)  Can be metallic or semiconducting depending on their geometry.
  6. 6. Diameter :- 1 nanometer Band gap :- 0-2ev A one atom thick layer of graphene into seamless cylinder . Their electrical conductivity can show metallic or semiconducting behaviour. A scanning tunnelling microscopy image of SWNT
  7. 7. Multi-walled nanotubes (MWNT) consist of multiple rolled layers (concentric tubes) of graphene. Interlayer distance :- 3.4 Å To describe structure of MWNT there are two models:- 1. Russian doll model 2. Parchment model
  8. 8. SWNT’s MWNT’s
  9. 9. There are three methods using which we can produce carbon nanotubes. 1. ARC DISCHARGE METHOD :-
  10. 10. 2. LASER ABLATION :-
  11. 11. 3. CHEMICAL VAPOR DEPOSITION (CVD) :-
  12. 12. Fiber material Specific Density Young's modulus(Tpa) Strength (Gpa) Strain at break(%) Carbon Nanotube 1.3 – 2 1 10 – 60 10 HS Steel 7.8 0.2 4.1 <10 Carbon fiber-PAN 1.7 – 2 0.2 – 0.6 1.7 – 5 0.3 – 2.4 Carbon fiber-Pitch 2 – 2.2 0.4 – 0.96 2.2 – 3.3 0.27 – 0.6 E/s-Glass 2.5 0.07 – 0.08 2.4 – 4.5 4.8 Kevlar-49 1.4 0.13 3.6 – 4.1 2.8 Mechanical Properties Properties of Conductive Materials Material Thermal conductivity Electrical conductivity Carbon Nanotube > 3000 10^6 – 10^7 Copper 400 6 x 10^7 Carbon fiber-Pitch 1000 2 - 8.5 x 10^6 Carbon fiber-PAN 8 - 105 6.5 - 14 x 10^6
  13. 13. Toxicity:- Under some conditions, nanotubes can cross membrane barriers, which suggests that if raw materials reach the organs they can induce harmful effects such as inflammatory and fibrotic reactions. Crystallographic defect:- As with any material, the existence of a crystallographic defect affects the material properties. Defects can occur in the form of atomic vacancies.
  14. 14. Electrical • Field emission in Displays • Application in electrodes, capacitors • Used in transistors • Nanocomputers Energy storage • Lithium batteries • Hydrogen storage Biological • Cancer treatment • DNA sequencing Applications
  15. 15. Fig : I-POD NANO Fig: TRANSFORMATION OF TRANSISTORS FROM HUGE SIZE TO NANO-CIRCUITS Fig: Intel’s 32nm Nehalem chip architecture Fig: Paper battery
  16. 16. Future Works • Difficult control of CNT – Diameter – Chirality – Density – placement • Improve resistivity of transparent SWNT films so that they are better than equally transparent, optimally doped ITO coatings. • Further price reductions of SWNT needed
  17. 17. In Conclusion… • There are many unique properties • Further investigation of toxicity is needed • There are many ways to synthesis • Method of synthesis depends on financial needs and amount of product desired • There are many exciting applications of carbon nanotubes due to their outstanding & novel properties
  18. 18. EN.WIKIPEDIA.ORG/WIKI/CARBONNANOTUBES WWW.SCIENCEDAILY.COM HOW STUFF WORKS – WWW.HOWSTUFFWORKS.COM IMAGES.GOOGLE.CO.IN/IMAGES WWW.UNDERSTANDINGNANO.COM/NANOTUBES- CARBON.HTML WWW.NANOCYL.COM › CNT EXPERTISE CENTRE WWW.PA.MSU.EDU/CMP/CSC/NANOTUBE.HTML

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