Carbon Nanotube Applications by pptfiles

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									J.-C. Charlier      Carbon Nanotube
                      Applications
                       Norma Rangel

                       Nanotechnology
                          3/2/2010



  Scott Dougherty
                                        University of Texas at Dallas
                            Outline
   Introduction
    – Properties
    – Fabrication processes
   Application of Carbon Nanotubes
    –   Electronic
    –   Unzipping of CNTs
    –   Structural and Mechanical: Composites
    –   Sensors, NEMS, Bio: Microscopy
    –   Biosensors: DNA sequencing
   Paper: Promises, facts and challenges for CNTs in
    imaging and therapeutics
   Future Work, conclusions
                                                 http://www.dbtechno.com


              Carbon nanotubes
   CNT is a tubular form of carbon
   Length: few nm to microns.
   CNT is configurationally equivalent to a two dimensional
    graphene sheet rolled into a tube.
   Can be functionalized
                            Outline
   Introduction
    – Properties
    – Fabrication processes
   Application of Carbon Nanotubes
    –   Electronic
    –   Unzipping of CNTs
    –   Structural and Mechanical: Composites
    –   Sensors, NEMS, Bio: Microscopy
    –   Biosensors: DNA sequencing
   Paper: Promises, facts and challenges for CNTs in
    imaging and therapeutics
   Future Work, conclusions
              Electrical properties
   Electrical conductivity six
    orders of magnitude
    higher than copper
    –     ‘tunable’ bandgap:
        electronic properties can be
        tailored through application
        of external magnetic field,
        application of mechanical
        deformation…
 Very high current carrying                How nanotechnology works
                                       CNT can be metallic (armchair)
  capacity                             or semiconducting, depending
                                       on chirality.
 Excellent field emitter
Mechanical Properties
   The strongest and most flexible molecular material because of C-C
    covalent bonding and seamless hexagonal network architecture
   Young’s modulus of over 1 TPa vs 70 GPa for Aluminum, 700 GPA
    for C-fiber
   Maximum strain ~10% much higher than any material
   Thermal conductivity ~ 3000 W/mK in the axial direction with small
    values in the radial direction




                                                                 Wikipedia
                            Outline
   Introduction
    – Properties
    – Fabrication processes
   Application of Carbon Nanotubes
    –   Electronic
    –   Unzipping of CNTs
    –   Structural and Mechanical: Composites
    –   Sensors, NEMS, Bio: Microscopy
    –   Biosensors: DNA sequencing
   Paper: Promises, facts and challenges for CNTs in
    imaging and therapeutics
   Future Work, conclusions
             Fabrication of CNTs
                                         - Patterned growth
   Chemical Vapor                       - Hydrocarbon feedstock
                                         - Growth needs catalyst
    Deposition (CVD)                     (transition metal)
                                         - Numerous parameters
                                         influence CNT growth




   DC arc discharge                     - SWNT, high purity,
                                         purification methods
    (Rice)

   Laser ablation
    (NEC, Japan)

                       [YK Choi, 2007]
SWCNTs on Patterned Surfaces
                  Surface masked
                   by a 400 mesh
                   TEM grid
                  Methane, 900° C,
                   10 nm Al/1.0 nm
                   Fe/0.2 nm Mo
(a) “Farms” of carbon
                                         Surface masked by a 400 mesh
nanotubes and (b) a closeup of        TEM grid; 20 nm Al/ 10 nm Fe;
one farm. Livermore is                nanotubes grown for 10 minutes
exploring the potential of such                 Grown using ethylene at 750o C
nanotube arrays for detection
applications.




 Christine Orme
                            Outline
   Introduction
    – Properties
    – Fabrication processes
   Application of Carbon Nanotubes
    –   Electronic
    –   Unzipping of CNTs and fibers
    –   Structural and Mechanical: Composites
    –   Sensors, NEMS, Bio: Microscopy
    –   Biosensors: DNA sequencing
   Paper: Promises, facts and challenges for CNTs in
    imaging and therapeutics
   Future Work, conclusions
    CNT Applications: Electronics
   CNT quantum wire
    interconnects                     Field emitters for
                                       instrumentation
   Diodes and transistors for
    computing                         Flat panel displays

   Capacitors                        THz oscillators

   Data Storage


                    •   Control of diameter, chirality
                    •   Doping, contacts
                    •   Novel architectures (not CMOS based!)
                    •   Development of inexpensive manufacturing processes


                                                 AMES Research center, NASA
Mechanism of carbon-nanotubes unzipping into
             graphene ribbons




(a-f) Gradual unzipping of a (5,5)
CNT. Pairs of oxygen atoms are
added sequentially. The edges of the
unopened (5,5) CNT are passivated
with hydrogen atoms and the
optimized structure (right) opens
only on the internal edge.
                                                              D. V. Kosynkin, et. al., Nature
                                                              London 458, 872 2009.
                                   Rangel et. al., JCP 2009
CNT Applications: Structural and
          Mechanical
    High strength composites
                                           Heat exchangers, radiators,
    Cables, tethers, beams                 thermal barriers, cryotanks

    Multifunctional materials             Radiation shielding

     Functionalize and use as             Filter membranes, supports
      polymer back bone
    - plastics with enhanced               Body armor, space suits
      properties like “blow molded
      steel”

                        -   Control of properties, characterization
                        -   Dispersion of CNT homogeneously in host materials
                        -   Large scale production
                        -   Application development

                                                      AMES Research center, NASA
      Production of sheets of carbon
           nanotube “textile”
                                                            Production up to 7
                                                             meters per minute
                                                            Transparent and
                                                             stronger than a sheet
                                                             of steel




http://www.gizmodo.com.au/2008/09/carbon_nanotube_manufa
cturing_breakthrough_could_mean_byebye_steel-2/

                                                       CSIRO and the University of Texas at Dallas
Dispersal of CNTs in Metal Matrix
“One of the major obstacles to the effective use of carbon nanotubes as
reinforcements in metal matrix composites is their agglomeration and poor
distribution/dispersion in the metallic matrix.” – Morsi & Esawi, 2007


   Ball Milling                               Dpowd = 70 μm (approx)
    – Most popular by far                      DCNT = 40 nm (approx)
    – Various times/rates
                                                                   Human hair
                                                                   (D~50 μm)
   Pestle and Mortar

   More Complex Processes
    – “Molecular Level Process”
    – Crucible-based process


                                                    9cm
                                                                [Feng et al, Mater. Cha. Eng, 2005]
    [Deng et al, Mater. Sci. Eng, 2007]   [Feng et al, Mater.
                                           Cha. Eng, 2005]



    [Feng et al, Mater. Cha. Eng, 2005]




Agglomeration of CNTs in a re-pressed
 composite containing 12% vol. CNT
                CNT Applications:
               Sensors, Microscopy
   CNT based microscopy:               Nanoscale reactors, ion channels

   Nanotube sensors: force,            Biomedical
    pressure, chemical, Biosensors       – in vivo real time crew health
                                           monitoring
                                         – Lab on a chip
   Molecular gears, motors,             – Drug delivery
    actuators                            – DNA sequencing
                                         – Artificial muscles, bone replacement,
   Batteries, Fuel Cells: H2, Li        – bionic eye, ear, human organs
    storage

                                     • Controlled growth
                                     • Functionalization with
                                       probe molecules, robustness
                                     • Integration, signal processing
                                     • Fabrication techniques
     CNT Applications: Microscopy
    Conventional silicon or tungsten tips wear out quickly.
    CNT tip is robust, offers amazing resolution.
1.    Small diameter – maximum resolution
2.    Excellent chemical and mechanical robustness
3.    High aspect ratio
       CNT as Functional AFM tips
Molecular-recognition AFM probe tips:
   Certain bimolecular is attached to the CNT tip
   This tip is used to study the chemical forces between
    molecules – Chemical force microscopy




                                 Institute of Optics, University of Rochester
    CNT Applications: Biosensors
   sensors for cancer diagnostics
   Identified probe molecule that will serve as signature of
    leukemia cells, to be attached to CNT
   Mechanism: Current flow due to hybridization will be
    through CNT electrode to an IC chip.
   Prototype biosensors catheter development


                               • High specificity
                               • Direct, fast response
                               • High sensitivity
                               • Single molecule and cell signal
                               capture and detection
         CNT Biological applications:
             DNA sequencing
   Nanotube fits into the
    major grove of the DNA
    strand
   Apply bias voltage
    across CNT, different
    DNA base-pairs give
    rise to different current
    signals
   With multiple CNT, it is                 Top view and side view of the
    possible to do parallel                  assembled CNT-DNA system
    fast DNA sequencing

                      Institute of Optics, University of
                                  Rochester                                  22
                            Outline
   Introduction
    – Properties
    – Fabrication processes
   Application of Carbon Nanotubes
    –   Electronic
    –   Unzipping of CNTs
    –   Structural and Mechanical: Composites
    –   Sensors, NEMS, Bio: Microscopy
    –   Biosensors: DNA sequencing
   Paper: Promises, facts and challenges for CNTs in
    imaging and therapeutics
   Future Work, conclusions
 Promises, facts and challenges for carbon
  nanotubes in imaging and therapeutics

             K. Kostarelos, A. bianco and M. Prato
       Nature nanotechnology | VOL 4 | OCTOBER 2009 |

Why CNTs?
 They can be easily internalized by cells and
  therefore can act as delivery vehicles for a
  variety of molecules relevant to therapy and
  diagnosis.
 As produced CNTs are insoluble in most organic
  or aqueous solvents, therefore for biological
  applications the surface should be modified.
 Toxicity effects are under debate
 the degree of aggregation and the
  individualization of nanotube materials in the
  biological milieu (blood, intraperitoneal,
  interstitial fluids, and so on) have an important
  role in their pharmacological performance.
 Physical properties of CNTs allow efficient
  electromagnetic stimulation and detection.

    Advantages of CNTs over nanoparticles:
1.   Larger inner volumes – can be filled with chemical or
     biological species.
2.   Open mouths of nanotubes make the inner surface
     accessible and can be modified.
   Types of carbon nanotube studied
    in vivo for imaging and therapy.
All in vivo studies using CNT so far have used one of these types:




   Pristine CNTs

                     Coated CNTs (non-covalent surface modifcation)




   Functionalized CNTs (covalent surface modifcation)
     Preclinical in vivo studies using
            carbon nanotubes
The majority of preclinical models have focused on oncology
    CNTs toxicity in biomedicine
 Focused in pristine CNTs, administrated by
  pulmonary routes.
 Material, doses and administration are not
  relevant to medical applications.
 Evidence of prolonged accumulation of
  long, rigid pristine CNTS associated with
  Cancer risks.
   Toxicity studies of CNTs
developed for medical imaging
         and therapy
                CNTs in Medicine Q&A
Are carbon nanotubes really useful in medicine?
Proof-of-principle studies indicate that carbon nanotubes may help
   treat various diseases (cancer, AIDS, malaria, metabolic diseases),
   but only one study so far has reported a therapeutic outcome
   (prolonged survival) in a preclinical human-tumour model.
 Challenges:
     – Nanotubes may not treat disease more effectively than established
       technologies.
     – The risk-to-benefit ratio offered by nanotube-based therapeutics and
       diagnostics may weigh towards the risk.
   Opportunities:
     – The possible contributions of nanotubes in medicine are almost unlimited and
       wide-ranging, from advanced delivery systems, electrodes and biosensors to
       probes for diagnostics and treatment- monitoring devices.

Can carbon nanotubes help cure cancer?
It is too early to determine because only early-stage preclinical studies
    are available and at present there are no clinical studies underway.
              CNTs in Medicine Q&A
Can carbon nanotubes act as ‘nanorobots’ in the blood stream?
A: Injectable nanorobots have not yet been developed, and active
   navigation of nanoparticles in the blood stream has not been
   achieved. Therefore, nanotubes can neither act as nanorobots nor
   be navigated in the blood stream.

   Challenges:
     – Nanotubes as components of nanorobots and other nanomachines that
       may accumulate and intoxicate the body.
   Opportunities:
     – Carbon nanotubes can act as components of nanofabricated
       machinery and offer tremendous capabilities — for example in
       wireless communication and monitoring between the patient and the
       clinician.
               CNTs in Medicine Q&A
Are carbon nanotubes biocompatible and what does that
  mean?
The term ‘biocompatibility’ implies the ability to interact with the biological
   milieu without adverse reactions.
Chemically functionalized nanotubes have been shown by many groups to be
   more biocompatible (no immune or acute inflammatory responses) than
   pristine nanotubes.

   Challenges:
     – Some types of carbon nanotubes or their impurities may accumulate
       in the body, leading to deposits that may cause unwanted side effects
       in the long-term.
   Opportunities:
     – New carbon nanotube materials and strategies to make them
       biocompatible are actively pursued.
CNTs for imaging and therapy Q&A
Are carbon nanotubes toxic?
Toxicity depends strongly on the type of nanotube, the dose, the route of
    administration and the tissue that is most affected.
Pristine nanotubes have been shown to activate various mechanisms
    associated with toxicity, however these effects are shown to be remarkably
    reduced when properly functionalized with chemical groups.
So far, no in vivo study using the types of nanotubes developed for medical
    purposes has reported adverse effects.
   Challenges:
    – The structural similarity and association between carbon nanotubes and
      the carcinogenic asbestos fibres
   Opportunities:
    – Systematic toxicological studies of carbon nanotubes to make them the
      ‘standard’ fibrilar nanomaterial.
    – Need to determine the extent of toxicological risks from using
      nanotubes, their doses, types and route of administration.
http://www.cheaptubes.com/carbon-nanotubes-
 prices.htm#Single_Walled_Nanotubes_Prices
                     Future Work
1.    Already in product: CNT tipped AFM
2.    Big hit: CNT field effect transistors based nano
      electronics.
3.    Futuristic: CNT based OLED, artificial muscles
4.    Comparison with well stablished alternatives

    Challenges
       Improve dispersion of carbon nanotubes in matrices
       Improve bonding to matrix
       Manufacture: Important parameters are hard to
        control.
       Large quantity fabrication process still missing.
       Manipulation of nanotubes.
  Thanks!

Questions?
                  G5
Rebuttal: Carbon-Nanotubes Applicattions

            Norma L. Rangel
              Norma Rangel – Rebuttal
• The overall presentation was good. However, from my point of view, it
  would have been better if instead of presenting that large variety of
  applications, the presentation have focused on maybe one or two and
  discuss more about the experimental details such as functionalization
  process the change in properties after functionalization and the physics
  behind each process.
    – I understand this concern, however, the topic was “CNTs” which made it to
      wide and broad, therefore I tried to present as much as information as I could.

• Nevertheless no application was analyzed carefully enough, I mean the
  methodology and results were not analyzed in detail. The basic working
  principle used in the applications was not illustrated.
    – The purpose of my presentation was to give an overview to the audience
      (mostly undergraduate students) some insights about CNTs basics and
      applications, which included a fair amount of information from several papers.
      I understande the reviewer’s concern but I think this could be solve if the
      audience were more uniform, that is, with the same background and level,
      also more technical lectures about for example specific fabrication process.

• The challenges shown in the last slide were general problems currently
  faced to make CNTs applications commercially available. The presenter
  didn’t make any suggestion on how to solve those problems.
    – Right, my personal opinion about CNTs was not shown in the presentation, I
      would rather use other materials such as graphene to replace CNTs.
• On the nanotube textile slide, how are nanotubes separated into the rope of
  nanotubes? More details on the initial process to grabbing the first few threads of
  NWs may help.
    – This is an interesting question, but unfortunately I don’t know the answer and I check
      my references and is not mentioned anywhere, we would need to contact the authors in
      order to get this information.

• Is the “preclinical human-tumor model” on the slide 32 a computer model
  simulation or a biological experimental model?
    – Experimental, a tumor is grown in a laboratory.

• What makes CNTs good candidate over other materials/structures for a biomedical
  device?
    – Due to the nanometer size of the nanotube -> can be introduce in the cells.
    – Tube shape -> useful to place the treatment inside and drug delivery.
    – Properties -> Strength, stability under harsh conditions. Spectroscopy and fluorescence
      detection.

• Are there any other structures or materials that can also be used for the
  applications discussed in the presentation?
    – Nano-particles have shown good performance for cancer treatment and have been
      already applied in current biomedical technologies.
            G1
Review of Carbon-Nanotubes
       Applicattions
      by Edson Bellido
The presenter explained the synthesis methods currently being used, the most important
properties of carbon nanotubes and a vary large variety of applications, focusing
principally on the used of CNTs for imaging and therapeutics. She point out the challenges
and opportunities of using CNTs in vivo.
The presenter discuss about the
importance of the
functionalization of CNT to be able
to use it in medicine applications
since the CNTs by itself are not
soluble on water and form
bundles that could be toxic and
                                          http://www2.polito.it/ricerca/micronanotech/act/immagini/cnt_01.jpg
can accumulate in the organs.
                                        The overall presentation was good. However, from
                                        my point of view, it would have been better if
                                        instead of presenting that large variety of
                                        applications, the presentation have focused on
                                        maybe one or two and discuss more about the
                                        experimental details such as functionalization
                                        process the change in properties after
                                        functionalization and the physics behind each
                                        process.
                    Review of CNTs applications lecture


It was summarized very well the physical properties of CNTs which
makes it an outstanding material.

A very broad range of applications for carbon nanotubes was shown.
Nevertheless no application was analyzed carefully enough,
I mean the methodology and results were not analyzed in detail.
The basic working principle used in the applications was not illustrated.

The challenges shown in the last slide were general problems currently
faced to make CNTs applications commercially available. The presenter
didn’t make any suggestion on how to solve those problems.




                                                     Alfredo D. Bobadilla
        Review:
Carbon Nanotube
    Applications
          By Mary Coan
 Overall a GREAT presentation
 Carbon Nanotubes have many properties
  that can not be found in any other
  material
 Have many applictions:
    ◦ Diodes, Capacitors, Flat panel displays, etc…
   Challenges were discussed
    ◦ Control of diameter
    ◦ Manufacturing costs
   Explained many different applications,
    processes, mechanisms and challenges

Review
   Discussed typical questions regarding
    CNTs
    ◦ Example: CNTs in Medicine (Good?)
 Discussed the opportunities and
  challenges for each question discussed
 The toxicity of CNTs was discussed
 She did a wonderful job by using many
  images to describe what she was
  discussing.
 The level of the work presented fits the
  audience very well.
Review
Review Carbon Nanotubes (G5)

     Diego A. Gomez-Gualdron
CNT properties
     • Outstanding electrical conductivity
     (six times copper)

     • Outstanding mechanical properties
     (tensile strength, yet flexible)

     •Field emitters (they can increase
     resolution in spectroscopy)

     •One-dimensional thermal
     conductivity

     •Easy functionalization

     •Enhanced mass transport through the
     nanotube
             Production methods

      Large scale               CVD schematics

                                                         Precursor gas
                             Substrate
•Chemical Vapor Deposition                   Nanotube




                                             catalyst


     Small scale

     •Laser Ablation
                                  Modified from ASIN group


     •Arc discharge
                 Applications
• Microchips elements of reduced size

• Composite materials for extreme conditions

• Nanosensors for chemical and medical applications

• Drug delivery and cancer treatment
                Assessment
• Electronic applications depending on selective
  production of pure semiconductor/conductor
  nanotubes at large scale

• Biomedical applications still have to solve
  citotoxicity issues and treatment effectiveness

• Mechanical applications pending on nanotube
  cost issues
                       Review
• A good presentation overall. A wide range of applications
  were shown. Good assessment of status and challenges for
  each application. Good fluency despite the recurrence of
  filler words and mumbling during slide transitions. The
  speaker was confident during the presentation, although
  not so much during questions. The figures/text balance on
  the slides could improve

• It would have been nice to stress what particular property
  of the nanotube is being taken advantage of for each
  specific application (why is the nanotube used for that
  specific application and not another material)
Review for G5

 Jung Hwan Woo




     Jung Hwan Woo
                    Questions
• On the nanotube textile slide, how are nanotubes
  separated into the rope of nanotubes? More details on
  the initial process to grabbing the first few threads of
  NWs may help.
• Is the “preclinical human-tumor model” on the slide 32
  a computer model simulation or a biological
  experimental model?
• What makes CNTs good candidate over other
  materials/structures for a biomedical device?
• Are there any other structures or materials that can
  also be used for the applications discussed in the
  presentation?

                         Jung Hwan Woo

								
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