1. CARBON NANO TUBES AND THEIR APPLICATIONS
PRESENTED BY
SRI PRANJAL BARMAN
DEPT. OF ELECTRONICS SCIENCE

2. INTRODUCTION
CARBON NANOTUBE HAS AN INTENSE RESEARCH OVER WORLD BECAUSE OF THEIR PHYSICAL AND CHEMICAL PROPERTIES ARE MUCH MORE SIMILAR TO THE OTHER EARTH MATERIALS

3. UNIQUE ROLE OF CARBON IN NATURE
CARBON PLAYS A UNIQUE ROLE IN
NATURE THAT IS HAS THE CAPABILITY TO FORM DIFFERENT NETWORKS IS
FUNDAMENTAL TO ORGANIC
CHEMISTRY AND THE VERY BASIS
FOR EXISTENCE OF LIFE

4. ALLOTROPES OF ELEMENTAL CARBON
TWO DIMENTIONAL
THREE DIMENTIONAL
ONE DIMENTIONAL
ZERO DIMENTIONAL

5. WHAT ARE CARBN NANO TUBES ?
CNT ARE THE ONE DIMENTIONAL ALLOTROPES OF CARBON
THEY ARE CYLINDRICAL STRUCTURE BASED ON HEXAGONAL LATTICE OF CARBON ATOMS
DICOVERED BY DR. SUMIO LIJIMA AT NEC LABORATORY IN 1991
HAVING LENGTH TO DIAMETER RATIO EXCEEDS 10000

6. STRUCTURE THE CHEMICAL BONDING OF NANOTUBES ARE COMPOSED OF SP2 BOND
CNTS NATURALLY ALIGN THEMSELVES INTO “ROPES” HELD TOGETHER BY “VAN DER WAAL’S” FORCE

7. ROLLING OF NANO TUBES
CNTS CAN BE CONSIDERED AS ROLLED-UP GRAPHENE SHEETS
WRAPPING OF GRAPHENE IS DETERMINED BY A PAIR OF INDICES (n,m)

8. METHODS OF ROLLING
TWO ATOMS OF THE GRAPHENE SHEET ARE SELECTED AS THE ORIGIN
DURING THE ROLLING THE TWO ATOMS ARE COINCIDE
ROLL-UP VECTOR IS KNOWN AS CHIRAL VECTOR (Cn)

9. MAPS OF WRAPPING

11. ARMCHAIR
ZIGZAG
CHIRAL
m = n
m = 0

12. TYPES OF CNTS
CARBON NANOTUBES ARE BROADLY CATAGORISED INTO TWO TYPES:-
1.SINGLE WALLED NANO TUBES
2.MULTI WALLED NANO TUBES

13. SINGLE WAL NANO TUBE
SWNTS ARE CONCEPTUALIZED BY WRAPPING OF A SINGLE GRAPHENE SHEET

14. MULTIWAL NANO TUBE
MWNTS CONSIST OF MULTIPLE LAYERS OF GRAPHENE SHEETS

15. SOME OF THE PROMINENT METHODS FOR CNT SYNTHESIS
1. CARBON ARC DISCHARGE
2. LASER-VAPORISATION TECHNIQUE
3. CHEMICAL VAPOUR DEPOSITION
4. ELECTROLYSIS

16. 1.CARBON ARC DISCHARGE
IT USES TWO ELECTRODES THROUGH WHICH DC IS PASSED IN AN INERT He ATMOSPHERE

17. 2.LASER VAPORISATION
IT USES CONDENSATION OF CARBON GENERATED FROM VAPORISATION OF GRAPHITE TARGETS.SWNTS ARE FORMED WHEN GRAPHITE CONTAINS CATALYSTS LIKE Ni,Cu,Pt ARE VAPOURISED BY LASER

18. 3.CHEMICAL VAPOUR DEPOSITION
CATALYTIC VAPOUR DECOMPOSITION IS DONE TO PRODUCE CARBON FIBERS

19. 4.ELECTROLYSIS
MWNTS ARE FORMED WHEN A CURRENT IS PASS THROUGH TWO GRAPHITE ELECTRODES IMMERSED IN MOLTEN IONIC SALTS AT 6000C

20. MECHANICAL PROPERTIES :
CNTS ARE THE STRONGEST AND STIFFEST MATERIAL IN EARTH.THE YOUNG’S MODULUS IS 1 TERA PASCAL & ESTIMATED TENSILE STRENGTH IS 200 GIGA PASCAL

21. ELECTRICAL PROPERTIES
FOR A GIVEN (n,m) CNTS EXHIBITES METALLIC OR SEMICONDUCTING PROPERTIES
METALLIC NANO TUBES HAVE CURRENT DENSITY 1000 TIMES GREATER THAN METAL SUCH AS SILVER & COPPER

22. BAND STRUCTURE OF NANO TUBES
IF THE VALUE OF (n – m) IS A MULTIPLE OF 3 THEN THE CNT IS METALLIC OTHERWISE THEY ARE SEMICONDUCTING
BAND STRUCTURE OF NANO TUBES
ALL ARMCHAIR (n = m) CNTs ARE METALLIC E Ef
ARMCHAIR
ZIGZAG

23. KINETIC PROPERTY
MULTIPLE CONCENTRIC NANO TUBES EXHIBIT A STRIKING TELESCOPING PROPERTY WHEREBY AN INNER NANOTUBE CORE MAY SLIDE ALMOST WITHOUT FRICTION

24. THERMAL PROPERTY
CNTS ARE EXPECTED TO BE VERY GOOD THERMAL CONDUCTOR ALONG THE TUBE
CNTS WILL BE ABLE TO TRANSMIT UP TO 6000 WATTS PER METER PER KELVIN AT ROOM TEMPERATURE

25. APPLICATIONS
MANY POTENTIAL APPLICATION HAS BEEN PROPOSED FOR CNTs.SOME OF THESE APPLICATIONS ARE NOW REALIZED IN PRODUCTS.OTHERS ARE DEMONSTRATED IN EARLY TO ADVANCED DEVICES.

26. CNT AS A CHEMICAL AND MECHANICAL SENSOR
SINCE THE CNT’S ELECTRONIC PROPERTY IS A STRONG FUNCTION OF ITS ATOMIC STRUCTURE, MECHANICAL DEFORMATION AND CHEMICAL DOPING CAN INDUCE STRONG CHANGE IN CONDUCTANCE.SUCH CHANGES CAN BE EASILY DETECTED BY ELECTRON CURRENT SIGNAL

27. FIELD EMISSION
HIGH ASPECT RATIO MAKES CNTS IDEAL EIELD EMISSION METARIAL
SCANNING PROBE TIPS

28. DISPLAY LARGE REDUNDANCY HIGH VEDIO RATE HIGHER POWER EFFICIENCY
WIDER OPERATING TEMPERATURE RANGE
FED

29. SEMICONDUCTOR DEVICE
CNTS ARE OUTSTANDING CANDIDATES FOR NOVEL ELCTRONICS DEVICES LIKE – CNT-FET;NANOELECTRONIC DEVICES ETC.
CNT-FET

30. OTHER APPLICATIONS
TODAY A LARGE NUMBER OF PRODUCTS USE CNT LIKE – X-RAY TUBE,Li-ION BATTERIES,VEHICLE FENDERS, GOLF CLUBS ETC.
WEAVING THEM INTO CLOTHES TO CREATE SLAB AND BULLETPROOF
COMPONENTS OF ELECTRICAL CIRCUIT
DRUGS TRANSPORT INTO BODY
MECHANICAL MEMORY AND NANO MOTORS

31. PROGRESS SO FAR MOTOROLA HAS DEVELOPED OF CNTs AT LOW TEMPERATURE.
THEY HAVE GIVEN THE ABILITY TO DESIGN PRODUCTS AT MOLECULAR LAVEL TO ENHANCE SPECIFIC CHARACTERISTICS.

32. THANK YOU