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NC State UniversityY.T. Zhu

Carbon Nanotubes and Their Applications

Yuntian Zhu

Department of Materials Science & Engineering

North Carolina State University

Qingwen Li, Lianxi Zheng, Xiefei Zhang, Steve Doorn, Paul Arendt

Los Alamos National Laboratory

Los Alamos, NM 87545, USA

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Scope

Long individual carbon nanotubes

Long nanotube arrays

Super-strong carbon nanotube fibers

Others

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Long Carbon Nanotubes

Long nanotubes have advantages over short ones inmany applications

MEMS: metallic CNT for micro-electric motors

Sensors and other devices

Nano-electric cables

Nano-conductors for wiring electric devices

Scaffolding for neuron growth and tissue engineering

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Method: Chemical Vapor Deposition

Carbon Source: Ethanol

Catalyst: Iron (III) Chloride / ethanolSubstrate: Silicon

Carriergas: Forming gas (94%Argon+6%H2)

Temperature: 900rC

Gas flow rate: 20 cc/min

Long CNT Synthesis

Nature Mater. 3, 673-676 (2004)

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Ultralong Nanotubes Synthesized at LANL

4 cm long single wall nanotube

Nature Mater. 3, 673-676 (2004)

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AFM and Raman Characterization

AFM image of a segment of the 4-cmlong SWNT (image width: 5Qm).

The height profile, d = 1.4 nm

The Raman image and spectrum of a long

SWNT and G-peak line-shape.

Nature Mater. 3, 673-676 (2004)

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Some facts about the ultra-long SWNTs

Raman measured about 20 long SWNTs

Diameter range: 1.31-2.25 nm

Both semiconductor and metallic types exist

All are single wall nanotubes (SWNTs)

Growth rate: 11 Qm/s

1.8 million atoms per second (d=1.4 nm)

Nature Mater. 3, 673-676 (2004)

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An Intramolecular Junction

Metallic

Semiconductive

Phys. Rev. Lett. 94, 016802 (2005). Our work

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Temperature-mediated junctions

Nature Materials, 6, 283, 2007

Beijing University & LANL

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Electrical properties of an S-S junction

Nature Materials, 6, 283, 2007

Beijing University & LANL

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Long Carbon Nanotube Arrays

4.6 mm array

Substrate 1 mm1Qm

20nm

Advanced Mater. 18, 3160-3163 (2006)

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Ribbons from CNT arrays and spun CNT fiber

Ribbons being pulled from array

Example of spun CNT fiber

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Comparison of commercially available structural engineering

materials(1) and CNT fibers(2)

1) A. Kelly, Concise Encyclopedia of CompositeMaterials, Pergamon, Oxford, UK, 1995

2) D: M Zhang, et al, Science 306 1358 (2004). C: M Motta, et al, Nano Lett. 5 1529 (2005). T: X. Zhang et al,Adv.

Mater. (2006).

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Comparison of LANL CNT Fiber with Current Materials and Work

from Other Groups

Advanced Mater. 18, 3160-3163 (2006)

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Carbon nanotube cotton

Substrate length = 35 mm

White, fluffy and spinnable

Advanced Mater. 19, 2567-2570 (2007)

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The CNT cotton is hydrophobic

100 Qm

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Spinning CNT fiber from the CNT cotton

50 Qm

Advanced Mater. 19, 2567-2570 (2007)

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Mechanical properties of the CNT fiber

Tensile stress-strain curveFracture mode

Advanced Mater. 19, 2567-2570 (2007)

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ColossalCarbon Tubeswith Walls of RectangularMacro-Pores

Phys. Rev. Lett.101, 145501 (2008)

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Phys. Rev. Lett.101, 145501 (2008)

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Some aerospace applications of CNT fibers

100,000km

62,000miles

Strength requirement: 100 GPa

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Other Applications

Documents

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