CNT Manufacturing Study Products · CNT Manufacturing, NSF 11/3/06 Objectives of Panel Study of CNT...
Transcript of CNT Manufacturing Study Products · CNT Manufacturing, NSF 11/3/06 Objectives of Panel Study of CNT...
CNT Manufacturing, NSF 11/3/06
Carbon Nanotube Manufacturing 2006:
Introduction and Overview
Peter C. Eklund
CarboLex, Inc.,&
Dept’s of Physics and Mat. Sci. EngineeringPenn State University
CNT Manufacturing, NSF 11/3/06
CNT Manufacturing Study Products
– North American Workshop Baseline Report– Final Workshop on Panel’s Assessment– Final Assessment of International CNT Manufacturing and
Applications• Disseminated by web and hardcopy
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CNT Manufacturing, NSF 11/3/06
Objectives of Panel Study of CNT Manufacturing in North America and Asia
– Clarify research opportunities and needs for promoting progress in the field generally
– Identify opportunities for international collaboration and mechanisms for achieving success
– Evaluate the position of foreign research programs relative to those in the U.S.
– Indicate where successes have been made and obstacles identified
– Provide government decision-makers and the research community with data to move CNTs into the marketplace
CNT Manufacturing, NSF 11/3/06
WTEC CNT Panel Members
• Peter Eklund*, Panel Chair,Physics & Mat Sci Eng’ingPenn State University
• Apparao Rao*, Physics, Clemson University• Pulickel Ajayan*, Material Sci & Engineering, RPI• Bhabendra Pradhan*, Columbian Chemical• Andrew Rinzler^, Physics, Univ of Florida• Jing Kong^, John Hart^, Electrical Engineering, MIT• Robert Blackmon^, Harper International, Inc
Site Visits, Workshop Area: *Japan , ^Korea, China
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CNT Mfg & Applic’s Panel Activities
• Organizational/Planning Meeting (NSF)• North American Baseline Workshop (NSF)• Asian Tour-Site Visits
– Japan– Korea– PR China
• Final Symposium/ Panel Findings and Recommendations (NSF)
• Final Report (published WTEC Website; HardCopy-Springer)
Team 2
Team 1
CNT Manufacturing, NSF 11/3/06
Asian Site Visits• South Korea
– Samsung– Yonsei University – Iljin Nanotech– Seoul National University
• PR China – Chinese Academy of Sciences – Peking University– Tsinghua University– National Center for Nanoscience and Engineering
• Japan– NanoCarbon Technologies (NCT) Ltd.– Shinshu University– Showa Denko K.K.– Riken National Laboratory– AIST Lab (Tsukuba)– NEC Lab (Tsukuba)– Chiba University – University of Tokyo
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Outline• Introduction to Carbon Nanotube (CNT) Structure,
Properties • Production of Single-Walled Tubes (SWCNTs) and
Multi-Walled Tubes (MWCNTs)• Purity Issues
– Large Batches of CNTs-what’s in there besides the tubes?– What Simple Characterization Tools tell us about SWCNTs and
MWCNTs
• Nanotube Applications• Executive Summary of WTEC Study on CNT
Manufacturing
CNT Manufacturing, NSF 11/3/06
Carbon: The Wonder Element
DWCNTSWCNTConesFullerenes C2n DiamondGraphite
Before 1985
Properties of Carbon combined in SWCNTs: high electron mobility, high thermal conductivity, high strength, low mass density
New NanoCarbons
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]2
3[tan 1
nmm
How to make Carbon NanotubesCarbon Nanotubes from Graphene
•Armchair: (n, n)
= 30
•Chiral: (n, m) (n m)
0 < < 30
•Zigzag: (n, 0)
= 0
21223 nmnmad cct
Courtesy of T. Hertel
CNT Manufacturing, NSF 11/3/06
(12,0)
“Zigzag” (n,0)
(7,7)
“Armchair” (n,n)
(9,5)
“Chiral” (n,m)
The Perfect Carbon Nanotube
(n,n): all metallic ; (n,m): 2/3 semiconducting 1/3 metallic
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E22
E11
Energy gap (Eii) vs tube diameter (d)
E11
Eii ~ 1/d
H. Kataura, et al., Synthetic Metals 103, 2555 (1999).
Electronic States
CNT Manufacturing, NSF 11/3/06
Characterizational Probes for CNT Quality
• Bulk Powders– SEM– Sheet Resistance (Ohms per square)– Gravimetric response to oxidation (TGA)– Raman Scattering/Photoluminescence (Chirality Maps)– Optical Absorption
• Single tube– High Resoultion TEM– Resonant Raman Scattering – 4-probe Electrical Resistivity, Back-gated FET
transconductance; thermal conductivity– Young’s Modulus
We need standards for nanotube quality!! NIST,NASA
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CNT Growth
•Growth by high temperature interaction of carbon vapor or hydrocarbon feedstock with nanoparticles containing Fe,Ni,Co + X
•Lingering arguments over the details of the growth model
•Growth Model needed if monodisperse (n,m) material are ever to be made
CNT Manufacturing, NSF 11/3/06
Growth: Small vs. Large Catalyst Particles
dia~ 4-20 nm
bundles of SWNTs
Multi-Walled Nanotubes (MWNTs)
dia > 30 nmdia < 4 nm
individual SWNT
Endo et al.Smalley et al.
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Growth Methods for SWCNTs
• Chemical Vapor Deposition – Batch process; highest purity,low T--more wall defects,
long tubes, best control of diameter distribution
• Arc Discharge and Plasma– Batch process, larger scale production, high-T—less wall
defects, lower purity, shorter tubes
• Pulsed Laser Vaporization– Batch process, low production (except FEL), high T- less
wall defects
CNT Manufacturing, NSF 11/3/06
“The automatic ARC”
SWNT Research Chamber at CarboLex-Broomall(PA) facility SWNT Research Chamber at CarboLex-Broomall(PA) facility
www.CarboLex.com
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CNT Manufacturing, NSF 11/3/06 Hata, et. al, SCIENCE, 306, 1362-1364 (2005)
CVD Approach: H2O-Assisted “Super Growth”
CNT Manufacturing, NSF 11/3/06
Large Batches of SCWNTs:(What’s in there?)
• Many different chiralities (n,m) • Other carbon phases (e.g., amorph. carbon)• Growth catalyst (metals)• Wall defects (missing C-atoms)• Wall functional groups (-COOH)• Hetero-atoms (boron,nitrogen)
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10 nm
d=1.35 nm
d=1.3 nm
HRTEM: SWNTs from the Jeff Lab FEL
P.C. Eklund, B. Holloway and M. Smith et al. , NanoLett. (2002)
CNT Manufacturing, NSF 11/3/06
Raman Scattering: One SWCNT
G.Chen and P.C. Eklund, unpublished
Radial mode ~ 1/dia
4 “G”-bands activated by cylindricalsymmetry
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Heating rate: 5 ˚C/min in dry air; Gas (air) flow rate: 100 cc/min; data courtesy of B. Pradhan
100
90
80
70
60
50
40
Wt l
oss (
%)
800600400200Temperature
8x10-3
6
4
2
0
-dM/dt
( C)
Gravimetric Analysis of Unpurified SWCNT Powder
Controlled Oxidation
2C+O2-> 2COdM/dTM(T)
Multishellcarbons
SWCNTs
Amorphous carbon
c.f., pub’s by P.C. Eklund, B. Pradhan et al.
CarboLex SWCNTs)
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Do All SWCNT Applications Require the Same Purity Material?
• Of course not!! • High-level purification leads to
significant manufacturing costs• Selectively remove impurities that
affect product performance
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SWCNT Purification and De-bundling Process
•We know how to do it
•It’s really now in the hands of chemical engineers to scale it up
Purification
De-bundling
c.f., pub’s by P.C. Eklund, B. Pradhan, C. Furtado, et al.
CNT Manufacturing, NSF 11/3/06
What’s bonded to the tube walls?
Carbon. Vol. 31, No.5, 721Angew. Chem.Int. Ed. 2002, 41, No.11
IR Spectroscopy is sensitive to functional groups on the SWCNT tube wall; Raman scattering is sensitive to wall defects, diameter and with difficulty (n,m)
c.f., pubs with Furtado, Kim, Eklund et al.
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Growth of MWCNTs
• CVD- “Endo” continuous process• Large scale production, tons per year• CNTs produced with wall defects and metal
impurities• High temperature treatment is last step in
production– Wall defects annelaed– Metal impurities vaporized and transported away
• Final product is high purity; low wall defects
CNT Manufacturing, NSF 11/3/06
What do Nanotubes do well?
Structural Composites
Tips for NanoProbes
FieldEmission
Transistors
ElectroMechanicalActuators
LogicGates
Battery Electrodes, Capacitors,EMI
GasStorage
Bulk Electronics
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Summary• Single-Walled Carbon Nanotubes (SWCNTs)
– still found difficult to make in large quantities and high purity
– high specific surface area- catalyst supports, gas storage– high electron mobility-single tube devices– High aspect ratio-sharp tips-FED devices– Percolating networks-touch screens, EMI shield, Solar panels
• Multiwalled Carbon Nanotubes (MWCNTs)– Now a high purity product @ tens of tons per year (Japan)– Electronic applications in bulk electronics
• Capacitors, SuperCapacitors, Batteries– Structural composites with plastics
• Sports equipment, Military?, Medical
CNT Manufacturing, NSF 11/3/06
CNT Race at a GlanceTOPIC
USA /North
America China Japan Korea
Bulk Growth MWCNT **** *** ***** * Bulk Growth SWCNT *** *** **** ** Structural Composites *** ? ***** ? Post Synthesis Processing *** * *** ** Conductive Composites EMI,touch screens, ink Emission Electronics
FED **** ? ? ***** Lighting ? ** ? ? X-Ray/Tubes ** ? ? ?
Electronic Devices **** * ** *** Battery ? ? ***** ? Capacitors ? ? ***** ? Industry/University Cooperative R&D ** **** ***** **** Targeted Government CNT R/D/M Funding * ? **** *** Government Funded University R&D (SWCNT) *** * *** ** Government Funded University R&D (MWCNT) ** ** ***** *
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