Carbon nanotubes ppt
- 1. Carbon Nanotubes Presented By:- Amal Ray Roll No:-02 Stream:-MTT GUIDED BY-Sajal Burman GETTS, Serampore
- 2. What Are They? •Allotropes of carbon with a cylindrical structure •Can be capped on the ends with buckyballs or open ended •Composed entirely of sp2 bonds
- 3. Why Should We Care? • Unique properties • Material of the future • Seemingly infinite applications • Possible health issues http://www-ibmc.u-strasbg.fr/ict/images/CNT_Peptide.jpg
- 4. Properties • 132,000,000:1 Length- To-Diameter Ratio • Diameter of 3 to 9 nm • Lengths in the millimeter range • Efficient electrical conductors • Can act as both thermal conductors and thermal insulators http://brent.kearneys.ca/wp-content/uploads/2006/05/carbon_nanotube.jpg
- 5. Strength SWNT compared to some common materials Young’s Modulus* Tensile Strength* Density* Steel 5 30 0.167 Kevlar 10 3 0.9 Rubber 10,000 700 Polypropylene 500 500 1.5 Glass 750 220 0.5 *Values = (Carbon Nanotube Property) / (Material Property)
- 6. Toxicity • Research is still in the early stages • In rodents, carbon nanotubes have been found to cause several lung issues • The needle-like shape of the fibers is similar to that of asbestos http://www.phy.mtu.edu/newsletter/research/FatNanotubes.jpg
- 7. Single-Wall Nanotube (SWNT) Armchair Zig-Zag
- 8. Multi-Walled Nanotubes (MWNT) • Multiple rolled layers of graphene sheets • More resistant to chemical changes than SWNTs http://www.siemens.com/innovation/en/about_fande/corp_technology/partn erships_experts/uc_berkeley.htm
- 9. Four Ways to Synthesize Carbon Nanotubes • Arc Discharge • Laser Ablation • Chemical Vapor Deposition (CVD) • Ball Milling http://students.chem.tue.nl/ifp03/synthesis.html
- 10. Arc Discharge • A direct current creates a high temperature discharge between two electrodes • Atmosphere is composed of inert gas at a low pressure • Originally used to make C60 fullerenes • Cobalt is a popular catalyst • Typical yield is 30-90% http://lnnme.epfl.ch/page80437.html
- 11. Ball Milling • Powder graphite is placed in a stainless steel container • Argon gas is used • Process occurs at room temperature • Powder is then annealed http://www.rsphysse.anu.edu.au/nanotube/
- 12. Combining Ball Milling and Vapor Deposition • Arkema France developed the process • Process generates the highest carbon purity • Products have improved dispersion http://nanopatentsandinnovations.blogspot.com/2009/12/arkema-combines- ball-milling-with-vapor.html
- 13. Electrical • Field emission in vacuum electronics • Application in electrodes, capacitors Energy storage • Lithium batteries • Hydrogen storage Biological • sensors • AFM tips • DNA sequencing Applications
- 14. Electrical Application: FED Field Emission Display ( FED) - Uses electron beam to produce color images (FED) - Traditionally cathode ray tubes are used but recently more focus on using carbon nanotubes - NASA is researching this technology to use in space exploration
- 15. Energy Storage: Lithium batteries • Nanotubes have the highest reversible capacity of any carbon material for use in Lithium ion batteries • Nanotubes have intrinsic characteristics desired in material used as electrodes in batteries and capacitors • Nanotubes are outstanding materials for super capacitor electrodes • They also have a number of properties including high surface area and thermal conductivity that make them useful as electrode catalyst supports in Polymer Electrolyte Membrane (PEM) fuel cells
- 16. Energy storage: Hydrogen storage • Single-walled carbon Nanotubes can store hydrogen • Nano tube technology will meet the challenge of storing hydrogen and releasing them adequately in hydrogen fuel car in future • Physisorption and chemisorption e mechanisms used for hydrogen storage in carbon nanotubes
- 17. Biological applications: sensing • Many spherical Nano-particles have been fabricated for biological applications. • Nanotubes offer some advantages relative to Nano-particles by the following aspects: 1. Larger inner volumes – can be filled with chemical or biological species. 2. Open mouths of Nano tubes make the inner surface accessible. 3. Distinct inner and outer surface can be modified separately.
- 18. Biological applications: AFM tips Carbon nanotubes as AFM probe tips: 1. Small diameter – maximum resolution
- 19. Biological applications: DNA sequencing • Nanotubes fit into the grove of the DNA strand • Apply voltage across CNT, different DNA base-pairs give rise to different current signals • With multiple CNT, it is possible to do parallel fast DNA sequencing Top view and side view of the assembled CNT-DNA system
- 20. Paper battery • Could easily be mistaken for a sheet of black paper • Functions as both a lithium- ion battery and a supercapacitor • Lightweight, thin, flexible • Can function at a wide range of temperatures
- 21. Nanotube speakers • Thin carbon nanotube films can act as speakers • New generation of cheap, flat speakers • Transparent, flexible, stretchable, and magnet free
- 22. Artificial muscles • Aerogels made from carbon nanotubes (CNTs) can serve as electrically powered artificial muscles • Sheet becomes 220% wider and thicker when voltage is applied • Flexes about 3 orders of magnitude faster and generates more than 30 times the force than human muscles of the same size
- 23. Nanotube thermocell • uses multiwalled carbon nanotubes as electrodes • 3 times efficient than conventional • Converts waste heat from industrial plants, pipelines into electricity
- 24. Nanotube Catalysts • Carbon nanotubes doped with Nitrogen • Reduce oxygen more effectively than platinum catalysts • Not susceptible to carbon monoxide poisoning, known to deactive platinum catalysts
- 25. In Conclusion… • There are many unique properties • Further investigation of toxicity is needed • There are many ways to synthesize • Method of synthesis depends on financial needs and amount of product desired • There are many exciting applications of carbon nanotubes
- 26. Questions?
- 27. References • www.ece.rochester.edu/courses/ECE580/docs/Nanotubes_Fu.ppt • www.ece.rochester.edu/courses/ECE580/docs/Nanotubes_Fu.ppt • http://www.nanowerk.com/spotlight/spotid=4154.php • http://www.azonano.com/details.asp?ArticleID=980#_Energy_Storage • http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6THY-493PC9C- 1&_user=952835&_coverDate=12/30/2003&_rdoc=1&_fmt=high&_orig=search&_ sort=d&_docanchor=&view=c&_searchStrId=1231942804&_rerunOrigin=google& _acct=C000049198&_version=1&_urlVersion=0&_userid=952835&md5=03c5f21cb 002be312d9fc81685b8914b • http://www.icdd.com/resources/axa/vol47/v47_33.pdf • http://lnnme.epfl.ch/page80437.html • http://students.chem.tue.nl/ifp03/synthesis.html • http://www.azonano.com/details.asp?ArticleID=1561 • http://nanopatentsandinnovations.blogspot.com/2009/12/arkema-combines-ball- milling-with-vapor.html
- 28. … THANK YOU