carbon nano-tubes in civil engineering

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Submitted By : ANKIT CHANDAN B.E. 7 TH CIVIL Roll No. : 1038-YCET-13 Presentation on the Presentation on the topic topic : : 1

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Page 1: Carbon Nano-tubes in Civil Engineering

Submitted By:ANKIT CHANDANB.E. 7TH CIVILRoll No. : 1038-YCET-13

Presentation on the topicPresentation on the topic : :

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Page 2: Carbon Nano-tubes in Civil Engineering

List of ContentList of Content : :• Introduction

• Types and Classification of CNTs

• Methods of Synthesis

• Properties

• Defects

• Applications

• Health Hazards

• Pros and Cons

• Scope

• Conclusion 2

Page 3: Carbon Nano-tubes in Civil Engineering

IntroductionIntroduction::• Carbon nanotubes (CNTs) are best described as a

seamless cylindrical hollow fibers, comprised of a single sheet of pure graphite, having a diameter of 0.7 to 50 nanometers with lengths generally in the range of 10’s of microns.

• Carbon nanotubes (CNTs) are microscopic molecules that contain bonds so strong relative to their size that they are used in nanotechnology.

• In 1952, the concept of CNTs was published in a Russian Journal. But was unnoticed as the article was published in Russian language.

• In 1991, the first CNT was synthesized by a Japanese researcher Sumio Ijima at NEC.

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Page 4: Carbon Nano-tubes in Civil Engineering

TypesTypes of CNTs: of CNTs:

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On the basis of Geometry

Page 5: Carbon Nano-tubes in Civil Engineering

Classification of Carbon Nanotubes :Carbon Nanotubes can be Carbon Nanotubes can be categorized by their categorized by their structures:structures:

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1. Single-wall Nanotubes (SWNT)

2. Multi-wall Nanotubes (MWNT)

Page 6: Carbon Nano-tubes in Civil Engineering

Methods of Synthesis of CNTs:

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Page 7: Carbon Nano-tubes in Civil Engineering

Properties of Carbon Nano-Tubes :Properties of Carbon Nano-Tubes :

• Very High Tensile Strength

• Very Elastic in Nature

• Highly Flexible; Can be bent considerably without damage

• High Electrical Conductivity

• High Thermal Conductivity

• Low Thermal Expansion Coefficient

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Page 8: Carbon Nano-tubes in Civil Engineering

Comparison of Mechanical Properties of Comparison of Mechanical Properties of CNT with other materials:CNT with other materials:

S. No.

Fiber Material Specific Density

Strength (GPa)

Strain at Break (%)

1. Carbon Nano-Tube 1.3 - 2 10 - 60 102. HS Steel 7.8 4.1 <103. Carbon Fiber- PAN 1.7 - 2 1.7 – 5 0.3 – 2.44. Carbon Fiber- Pitch 2 – 2.2 2.2 – 3.3 0.27 – 0.65. Fiber Glass 2.5 2.4 – 4.5 4.8

Table 1: Mechanical Properties of Engineering Fibers

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Page 9: Carbon Nano-tubes in Civil Engineering

Comparison of Transport Properties of CNT Comparison of Transport Properties of CNT with other materials:with other materials:

S. No.

Material Thermal Conductivity(w/m.k)

Electrical Conductivity

1. Carbon Nano-Tube

>3000 106 – 107

2. Copper 400 6 x 107

3. Carbon Fiber- Pitch

1000 2 – 8.5 x 106

4. Carbon Fiber- PAN

8 – 105 6.5 – 14 x 106

Table 2. Transport Properties of Conductive Materials

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Page 10: Carbon Nano-tubes in Civil Engineering

Defects in CNTsDefects in CNTs

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• Defects can occur in the form of atomic vacancies. High levels of such defects can lower the tensile strength by up to 85%.

• Because of the very small structure of CNTs, the tensile strength of the tube is dependent on its weakest segment in a similar manner to a chain, where the strength of the weakest link becomes the maximum strength of the chain.

Page 11: Carbon Nano-tubes in Civil Engineering

Applications of CNTs:• Cancer Treatment• Storage of Energy• Filled Composites• Sensors • Reinforcement of Turbine Blades• Coating• Water Purification• Artificial Muscles• Super Elevators• Data Storage

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Other Applications of Carbon Nano-Tubes :Other Applications of Carbon Nano-Tubes :

Page 13: Carbon Nano-tubes in Civil Engineering

Health hazards:Health hazards:• According to scientists at the National Institute of Standards and

Technology, carbon nanotubes shorter than about 200 nanometers readily enter into human lung cells similar to the way asbestos does, and may pose an increased risk to health.

• Carbon nanotubes along with the majority of nanotechnology, are an unexplored matter, and many of the possible health hazards are still unknown.

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Page 14: Carbon Nano-tubes in Civil Engineering

Pros:Pros:

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• Extremely small and lightweight.

• Resources required to produce them are plentiful, and many can be made with only a small amount of material.

• They function almost just as well in extreme cold as they do in extreme heat.

• Good field emission

• High aspect ratio.

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Cons:Cons:

• Despite all the research, scientists still don't understand exactly how they work.

• Extremely small, so are difficult to work with.

• The process is relatively expensive to produce the nanotubes.

• It would be expensive to implement this new technology in and replace the older technology in all the places that we could.

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Page 16: Carbon Nano-tubes in Civil Engineering

Civil Engineering Scope:Civil Engineering Scope:

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• Considerable improvement in restricting cracks in cementitious matrices was observed by addition of CNTs in concrete.

• Used to increase the densification and hence mechanical properties and durability of cementitious materials.

• The service life of a structured can be doubled by using the CNTs.

Page 17: Carbon Nano-tubes in Civil Engineering

Conclusion:Conclusion:

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At the moment, nanotubes are too expensive and cannot be produced selectively. Some of the already known and upcoming techniques look promising for economically feasible production of purified carbon nanotubes.

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.

Carbon nanotubes could play a pivotal role in this upcoming revolution if their remarkable structural, electrical and mechanical properties can be exploited.

The remarkable properties of carbon nanotubes may allow them to play a crucial role in the relentless drive towards miniaturization scale.

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

Page 18: Carbon Nano-tubes in Civil Engineering

References:• https://www.google.co.in/#q=latest+innovations+in+civil+engineering

• https://en.wikipedia.org/wiki/Carbon_nanotube• https://scholar.google.co.in/scholar?

hl=en&as_sdt=0,5&as_vis=1&q=Carbon+Nanotubes+as+reinforcement+in+concrete

• http://www.academicpub.org/pnn/paperInfo.aspx?paperid=13890• https://en.wikipedia.org/wiki/

Potential_applications_of_carbon_nanotubes• https://nanoscalereslett.springeropen.com/articles/10.1186/s11671-015-

1056-3

• https://dspace.mit.edu/handle/1721.1/51568 18

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