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Presented by-Amiya Kumar Jana

CARBON NANO TUBES: PROPERTIES AND

APPLICATIONS

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CONTENTSOver Views of CNTsProperties of CNTsApplications of CNTsChallengesSummarySources

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Over Views of CNTs What are CNTs?o Carbon nanotubes (CNTs) are allotrope of

Carbon with a cylindrical nanostructure.o Carbon nanotubes (CNTs) are best described as

a seamless cylindrical hollow fibers, comprised of a single sheet of pure graphite (Graphene), having a diameter of 0.7 to 50 nanometers with lengths generally in the range of 10-100 of microns.

o Carbon nanotubes (CNTs) are made by rolling up of sheet of GRAPHENE into a cylinder.

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Grapheneo Graphene is basically a 2D single layer of graphite.o Graphene is stronger and stiffer than diamond. It,

however, can be stretched like rubber.o The C–C bond( 2) length in graphene is ~0.142 nm. 𝑠𝑝

The graphene sheets stack to form graphite with an inter planar spacing of 0.335 nm,

o Roll-up Graphene Carbon Nano Tubes

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History & Discovery • In June 1991, Japanese

scientist SUMIO IIJIMA NEC Laboratory in Tsukuba found an extremely thin needle-like material when examining carbon materials under an electron microscope.

• He named these materials “carbon nanotubes” since then name has been widely accepted.

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Types of Carbon Nanotubes Single-walled

Nanotubes(SWNTS)• A single-walled carbon nanotube

(SWNT) may be thought of as a single atomic layer thick sheet of graphene rolled into a seamless cylinder.

• Most single-walled nanotubes (SWNT) have a diameter of close to 3 nanometer, with a tube length that can be many 10^4 times longer.

Multi-walled Nanotubes (MWNTs)

• Multi-walled nanotubes (MWNT) consist of multiple rolled layers (concentric tubes) of graphite.

• MWCNTs can have OD ~ 20nm, ID ~ 3nm length can be 10^4 times longer.

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Structures of Carbon Nanotubes• The structure of a single-wall carbon

nanotube is specified by the vector called “Chiral vector”

• Depending on the chiral indices ( 1 , 2) and chiral angle(𝑛 𝑛 ɵ) SWCNT can be –

1. Zig-Zag (ɵ = 0)2. Arm Chair (ɵ=30)3. Chiral (0<ɵ<30) • Depending upon their different

structures, CNTs can exhibit metallic or semiconducting properties.

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SYNTHESIS OF CARBON NANOTUBES

Arc Discharge Method (1991)Laser Ablation (1995)Chemical Vapor Deosition (CVD)

(1993)HiPCo (1999)CoMoCat (2000)

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PROPERTIES OF CNTs

• Mechanical and Physical• Electrical and Electronics Properties• Thermal Properties

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Mechanical and Physical Properties

• Carbon nanotubes are the strongest and stiffest materials yet discovered in terms of tensile strength and elastic modulus respectively.

• This strength results from the covalent sp2 bonds formed between the individual carbon atoms which are stronger than 3D diamond bonds.

Young’s Modulus :• Lourie and Wagner experiment using bar model and reports

Young’s modulus of 2.8–3.6 TPa, for SWCNT and 1.7–2.4 TPa for MWCNT .

• Yu et al. obtained ranges from 320 to 1470 GPa (mean: 1002 GPa) for SWCNT and from 270 to 950 GPa for MWCNT using Direct tensile loading tests.

• The simply-supported beam model was used by Salvetat et al. to model the deflections of individual MWCNTs; a Young’s modulus of ~1 TPa for MWCNTs.

• Wong et al using cantilevered beam model obtained modulus of 1.28 ± 0.59 TPa for MWCNTs.

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Stress Versus Strain Curves

For SWCNTs For MWCNTs

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Strength of CNTs • Tensile load testing was

performed by Yu et al. on SWCNT bundles and tensile strength values ranging from 13 to 52 Gpa and maximum tensile strain obtained was 5.3% were reported.

• Yu et al. have also conducted tensile testing of MWCNTs. It was found that only the outermost layer breaks during the loading process. The tensile strength corresponding to this layer of CNT ranges from 11 to 63 GPa.

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Comparison of Mechanical Properties

Hardness Wetability Aspect Ratio

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Electrical and Electronics Properties

Behaviors According to Structure

• Chiral Vector• If 1= 2 the nanotube is 𝑛 𝑛

metallic• If (n1-n2) is a multiple of 3,

then the nanotube is semiconducting with a very small band gap, otherwise the nanotube is a moderate semiconductor.

Semiconducting and Doping

Piezoresistance Photoconductivity of

Carbon Nanotubes

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THERMAL PROPERTIES o The thermal

properties of carbon nanotubes are directly related to their unique structure and small size

Specific HeatThermal

conductivity

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APPLICATION OF CARBON NANOTUBES

Electronic Applications of Carbon Nanotubes

CNTs in Mechanical FieldCNT in MedicineOther applications of CNTs

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Electronic Applications of Carbon Nanotubes

• Conductive Composites

• Electron Emitters

• Nanoprobes

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Sensors • Biomedical Industry • Automotive Industry• Food Industry • Environmental

Monitoring FED DisplayTemplate

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CNTs in Mechanical FieldCNT Based Actuator• High technology applications, including

humanoid robots, artificial and damaged hearts, artificial limbs, medical prosthetic devices etc

CNT Based Composites• Polymer matrix composite• Ceramic matrix composite

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CNT in MedicalCNTs in Drug Delivery and Cancer

TherapyCNTs as Biosensors• CNT Network Bio-Stress Sensors • Glucose detection biosensors• DNA detection biosensors

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Other applications of CNTs CNTs Thermal

Materials CNTs Air and Water

Filtration Hydrogen Storage Energy Storage …

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CHALLENGES• Despite all the research, scientists still don't

fully understand exactly how they work.• Extremely small, so are difficult to work with. • Currently, the process is relatively expensive to

produce the nanotubes. • Level of purity is less in most of the synthesis

techniques.• Challenge is in the manipulation of nanotubes.

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Summary Their phenomenal mechanical properties, and unique

electronic properties make them both interesting as well as potentially useful in future technologies.

Nanotechnology is predicted to spark a series of industrial revolutions in the next two decades that will transform our lives to a far greater extent than silicon microelectronics did in the 20th century.

Lack of commercially feasible synthesis and purification methods is the main reason that carbon nanotubes are still not widely used nowadays.

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Sources1. https://en.wikipedia.org/wiki/Carbon_nanotube2. https://www.cheaptubes.com/carbon-nanotubes-

applications/ 3. www. nptel.ac.in/4. “Carbon Nanotubes: Properties and Applications”

Edited by Michael J. O’Connell, Ph.D. Senior Research Scientist, Theranos, Inc. Menlo Park, California.

5. “Electrical properties of Carbon Nanotubes” Kasper Grove-Rasmussen Thomas Jorgensen, August 28, 2000.

6. "Mechanical properties of carbon nanotubes: theoretical predictions and experimental measurements" Rodney S. Ruoff a, Dong Qian , Wing Kam Liu.

7. “Thermal properties of carbon nanotubes and nanotube-based materials”, J. Hone1, M.C. Llaguno, M.J. Biercuk, A.T. Johnson, B. Batlogg, Z. Benes, J.E. Fischer.

8. “Carbon Nanotube-Based Sensors” Niraj Sinha, Jiazhi Ma, and John T. W. Yeow.

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