Centrifugal Length Sorting of Carbon Nanotubes

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Centrifugal Length Sorting of Carbon Nanotubes

• Dr. Jeffrey Fagan

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Single Wall Carbon Nanotubes

• Nanotubes are rolled up sheets of graphite.
• How they are rolled up determines their
  electrical properties.
• The length can be from lt 10 nm to microns or
  more.
• Image courtesy of wikipedia.org

• Nanotubes (SWCNTs) come as a low purity mixture
  of many types and lengths.
• 10 30 Different Producers.
• Current price ? 200 - 750 / gram.

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Nanotube Market
Composites
Energy
Electronics
Medical
30 Major Producers
Chemical Engineering News Carbon Nanotubes By
The Metric Ton November 12, 2007, Volume 85 (46),
pp. 29-35

• Market is rapidly growing.
• Many potential applications.

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Market Problem
Composites
Energy
Electronics
10 50 Nanotubes
Medical
30 Major Producers

• There is a disconnect between SWCNT quality and
  applications needs.

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Market Problem
Composites
Energy
gt 90 Nanotubes
Electronics
10 50 Nanotubes
Purified
Medical
Separated

• Value addition in the processing.
• Some application require sorted material.

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Technology

• We invented a technology to use a centrifuge to
  sort mixtures of tubes into different lengths.
• Our technology allows the economical sorting of
  single wall carbon nanotubes (SWCNTs) by length.
• Technology works for all SCWNT types.

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Technology
Different types of long SWCNTs.

• At bench scale 10 mg / day separation is easy,
  and at lt 4 / mg total cost. Other separations
  typically cost 20 - 30 / mg or more.
• Our separation is scalable, current 10 mg /day is
  gt 20 X larger than any competitor technique

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Technology
Applications

• Longer SWCNTs have better optical and
• Better Properties ? higher value
• Sorting ? grades for different markets.

mechanical properties.
Purified
Separated
Raw Soot
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Applications

• Medical Applications
• Transparent Conductive Electrodes
• Other Electronics
• Super / Ultracapacitor material
• Flexible Electronics
• Circuitry
• RFID tags
• Other Energy
• Solar Cells
• Batteries
• Fuel Cells
• Energy Absorbing Material

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Applications
Medical Applications

• Length affects interactions with cells.

IMR 90 with gt 200 nm SWNTs (cyan) None enter the
cell in 16 hours
IMR 90 with lt 200 nm SWNTs (red) Large numbers
enter in lt 16 hours
IMR 90 Human Lung Cell Stained green for
visualization

• Only some SWCNTs are useful.
• Need to control the cell uptake.
• Less material ? fewer side effects.

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Medical Applications
Applications
Medical Sensors / Target Agents / Imaging Probes

• Market Sizes
• Target agents Cancer Drugs Alone ? 45 Billion
  in 2007
• Biosensors ? 5.1 Billion in 2006
• Ability to sense glucose and other commercially
  important bio-molecules already demonstrated
• Cost not an issue for medical applications, only
  the ability to meet required physical properties.
• Sorting reduces the amount required.
• Minimize EHS risks and liabilities
• Maximize chance of FDA regulatory approval
• Size selection allows for greatly enhanced
  properties or property targeting while
  substantial reducing the required amount of
  SWCNTs for a given goal.
• Size selection eliminates impurities that could
  otherwise limit or cause regulatory approval
  failure.

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Applications
Conductive Coatings

• SWCNTs offer a cheap replacement for ITO
• Current market for ITO is ? 1 Billion/year
• 10 annual growth forecast for the next 5 -6
  years.
• Sorted SWCNTs are tougher, flexible and more
  transparent than ITO
• Separation ? Multiple grades ? more value
  extraction.

Image courtesy of Apple
Images courtesy of Dell

• Short time to market, likely 1 - 3 years

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Reference Material to Support Technology in Early
2009

• NIST is planning several SWCNT reference
  materials (RMs) in FY 2009.
• Raw Soot, Purified and Size sorted populations
  based on this technology will be produced.
• These materials will allow for significant
  industrial advances in measurements, as well as
  traceability to NIST standards.

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Collaboration
Technical
Opportunities
Contact

• Dr. Kalman Migler
• NIST Polymers Division
• 100 Bureau Drive, MS 8542
• Gaithersburg, MD 20899-8542
• Tel [phone]
• Kalman.migler_at_nist.gov

Dr. Jeffrey Fagan NIST Polymers Division 100
Bureau Drive, Mail Stop 8542 Gaithersburg, MD
20899-8542 Tel [phone] Email
jeffrey.fagan_at_nist.gov