carbon nano tube dharesh

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CARBON NANOTUBES AND SOMECARBON NANOTUBES AND SOMEAPPLICATIONSAPPLICATIONS

PRESENTED BYPRESENTED BY

Dharesh KP(A120281002)(A120281002)

MTECH THIRD SEMESTERMTECH THIRD SEMESTER

AINT, NoidaAINT, Noida


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Carbon Nano TubesCarbon Nano Tubes

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Allotropes of carbon with Allotropes of carbon withcylindrical nanostructurecylindrical nanostructure

Diameter as small as 1nm;Diameter as small as 1nm;Length: nm to microns.Length: nm to microns.Configurationally equivalentConfigurationally equivalentto a 2 dimensionalto a 2 dimensional graphenegraphene sheet rolled into a tube.sheet rolled into a tube.

1970:1970: MorinobuMorinobu EndoEndo---- First carbon Nano TubesFirst carbon Nano Tubes1991:Sumio1991:Sumio IijimaIijima---- NEC Laboratory in TsukubaNEC Laboratory in Tsukuba-- --used highused high- -resolution transmission electron microscopyresolution transmission electron microscopyto observe carbon nanotubes.to observe carbon nanotubes.


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CarbonCarbon nanotubenanotube

CNT: RollingCNT: Rolling- -up aup a graphenegraphene sheet to form asheet to form atubetube

Schematicof a CNT

STM imageof CNT


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Carbon nanotubeCarbon nanotube

Properties depending on how it is rolled up.Properties depending on how it is rolled up.

a 1, a 2 are the graphene vectors.OB/AB overlaps after rolling up.OA is the rolling up vector.

21manaOA !


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Types of NanotubesTypes of Nanotubes

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Single walled

Multi walled

Nano buds


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H ow to make nanotubes?H ow to make nanotubes?Arc discharge Chemical vapor deposition Laser ablation (vaporization)

Connect two graphiterods to a power supply,place them millimeters

apart, and throw switch. At 100 amps, carbon

vaporizes in a hotplasma.

Place substrate in oven, heat to600 C, and slowly add a carbon-

bearing gas such as methane. As gas decomposes it frees upcarbon atoms, which recombine

in the form of NTs

Blast graphite with intense laser pulses; use the laser pulses rather than electricity to generate carbongas from which the NTs form; tryvarious conditions until hit on onethat produces prodigious amounts

of SWNTs

Can produce SWNT andMWNTs with fewstructural defects

Easiest to scale to industrialproduction; long length

Primarily SWNTs, with a largediameter range

Short with random sizesand directions

NTs are usually MWNTs andoften riddled with defects

By far the most costly, becauserequires expensive lasers


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Properties of CNTProperties of CNT

Strongest and stiffest materialsStrongest and stiffest materialsVery good thermal conductors (BallisticVery good thermal conductors (Ballistic

conduction)conduction)H igh temperature stability (2800H igh temperature stability (2800 00C inC invacuum and 750vacuum and 750 00C in air)C in air)

One dimensional electron propagationOne dimensional electron propagationalong tube axisalong tube axisMM--CNT show superconductivityCNT show superconductivity

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Mechanical propertiesMechanical properties

strong three folded bondingstrong three folded bonding of theof the curvedcurvedgraphenegraphene sheet, which is stronger than insheet, which is stronger than in

diamonddiamondParticularly stable against deformations.Particularly stable against deformations.The tensile strength of SWNTs=20 times that of The tensile strength of SWNTs=20 times that of

steel (equal to ~ 4 5steel (equal to ~ 4 5 GpaGpa))

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Tensile strength versus tensileTensile strength versus tensilemodulus formodulus for nanotubenanotube

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Very high tensile strength values are alsoVery high tensile strength values are alsoexpected for ideal (defectexpected for ideal (defect- -free) cfree) c- -MWNTs, sinceMWNTs, sincecombining perfect tubes concentrically is notcombining perfect tubes concentrically is notsupposed to be detrimental to the overall tubesupposed to be detrimental to the overall tubestrength, provided the tube ends are wellstrength, provided the tube ends are wellcapped (otherwise, concentric tubes could glidecapped (otherwise, concentric tubes could gliderelative to each other, inducing high strain).relative to each other, inducing high strain).

Tensile strength values as high as ~ 150GPaTensile strength values as high as ~ 150GPahave actually been measured for perfecthave actually been measured for perfectMWNTs from electric arcMWNTs from electric arc

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Flexural modulus, for perfect MWNTs shouldFlexural modulus, for perfect MWNTs shouldlogically exhibit higher values than SWNTs,logically exhibit higher values than SWNTs,with a flexibility that decreases as the number with a flexibility that decreases as the number of walls increases.of walls increases.Measurements performed on defective MWNTsMeasurements performed on defective MWNTsobtained from CCVD gave a range of 3obtained from CCVD gave a range of 3 --3 03 0GPaGPa. Tensile modulus, also, reaches the. Tensile modulus, also, reaches thehighest values ever, 1highest values ever, 1 TPa TPa for MWNTs, andfor MWNTs, andpossibly even higher for SWNTs, up to 1. 3 possibly even higher for SWNTs, up to 1. 3 TPaTPa. .

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Applications ApplicationsElectricalElectrical

Field emission in vacuum electronicsField emission in vacuum electronicsBuilding block for next generation of VLSIBuilding block for next generation of VLSINanoNano lithographylithography

Energy storageEnergy storageLithium batteriesLithium batteriesH ydrogenH ydrogen storagestorage

BiologicalBiologicalBioBio--sensorssensorsFunctional AFM tipsFunctional AFM tipsDNADNA sequencingsequencing

MechanicalMechanicalStructural composites (Boeing 787,buildings,etc)Structural composites (Boeing 787,buildings,etc)super super- -strong fabricsstrong fabricsspace elevator space elevator


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Biological applications: BioBiological applications: Bio- -

sensingsensingNanotubes offer some advantages relativeNanotubes offer some advantages relative

toto nanoparticlesnanoparticles by the following aspectsby the following aspects: :

Larger inner volumesLarger inner volumes can be filled with chemical or can be filled with chemical or biological species.biological species.

Open mouths of nanotubes make the inner surfaceOpen mouths of nanotubes make the inner surfaceaccessible.accessible.Distinct inner and outer surface can be modifiedDistinct inner and outer surface can be modifiedseparately.separately.


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Fluorescence of nanotubes canFluorescence of nanotubes can

be used to make biosensorsbe used to make biosensors

Light and the human bodyLight and the human body

Different wavelengths interactDifferent wavelengths interactwith tissue differentlywith tissue differently

Familiar with XFamiliar with X- -raysrays

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Sy stem Targetspecies

Salient feature Reference

Single wallnanotubes (SWNT) NH3 and NO 2

Sensitive to 200 ppm of NO 2, and 1% of NH 3.Scie

nce

287(2000) 1801.

Single wallnanotubes (SWNT)

N2, He , O2, and Ar

Gas concentrations as low as 100 ppm can bedetected

Appl. Phys. L ett .83 (2003) 2280.

M ulti-wall carbonnanotubes(M WCNTs)

NH 3 Gas concentrations as low as 10 ppm can bedetected. The sensor showed a reversibleres ponse of few minutes.

J . Phys. D: Appl. Phys. 36 (2003)L109.

P oly( o -anisidine)(P OAS) coatedCNT

HCl Nine ti mes increase in sensitivity co mp ared touncoated CNT

C he mic al Phys ic s Letter s, V o lume 383( 5-6) ( 2004)617.

M WNT-SiO 2 CO 2, O2and NH 3

Sensor res ponse ti me is a pproxi mately 45 s , 4min, and 2 min for CO 2,O2, and NH 3, res pectively.The sensor res ponse is reversible for O 2 and CO 2, but irreversible for NH 3

IEEE Se ns. J. 2 (2002 ) 82 .

Single-walledcarbon nanotube(SWNT)

-D-glucose

Senses -D-glucose in solution phase by twodistinct mechanis ms of signal transduction:fluorescence and charge transfer.

Na t . Ma ter . 4(200 5)86.

P oly(vinylferrocene) (PVF )M WCNTs

Glucose Glucose concentration in real blood sa mp le can be deter m ined.

T he Analys t 131 (200 6) 6 70 .

CNT based Nano SensorsCNT based Nano Sensors


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Biological applications: AFM tipsBiological applications: AFM tips

Carbon nanotubes as AFM probe tips:Carbon nanotubes as AFM probe tips:1.1. Small diameter Small diameter maximum resolutionmaximum resolution2.2. Excellent chemical and mechanical robustnessExcellent chemical and mechanical robustness3 .3 . H igh aspect ratioH igh aspect ratio

Resolution of ~ 12nm is achieved


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Biological applications:Biological applications:Functional AFM tipsFunctional AFM tips

Molecular Molecular- -recognition AFM probe tips:recognition AFM probe tips:Certain bimolecular is attached to the CNT tipCertain bimolecular is attached to the CNT tipThis tip is used to study the chemical forces betweenThis tip is used to study the chemical forces betweenmoleculesmolecules Chemical force microscopyChemical force microscopy


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CNT Based LampsCNT Based Lamps

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Lifetime 8000 H rsH igh efficiency

Field Emission DisplayField Emission Display


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Nano filtersNano filtersSmall pore sizeSmall pore sizeH igh Surface Area to Volume RatioH igh Surface Area to Volume RatioRemoves chemicalsRemoves chemicalsKills and removes bioKills and removes bio- -contaminantscontaminantsMonolayer Monolayer nanomeshnanomesh blocks debris withoutblocks debris withoutstopping water flowstopping water flow

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